Critical Reasoning

The number of people diagnosed as having a certain intestinal disease has dropped significantly in a rural county this year, as compared to last year. Health officials attribute this decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year and thus reduced the incidence of the disease.
Which of the following, if true, would most seriously weaken the health officials' explanation for the lower incidence of the disease?

A) many new water-treatment plants have been built in the last five years in the rural county.
B) Bottled spring water has not been consumed in significantly different quantities by people diagnosed as having the intestinal disease, as compared to people who did not contract the disease.
C) Because of a new diagnostic technique, many people who until this year would have been diagnosed as having the intestinal disease are now correctly diagnosed as suffering from intestinal ulcers.
D) Because of medical advances this year, far fewer people who contract the intestinal disease will develop severe cases of the disease.
E) The water in the rural county was brought up to the sanitary standards of the water in neighboring counties ten years ago.

we need to prove " reduction in diseased patients is not due to water plant improvement but due to some other reason"

At first look only B and C stands.. neglect the rest

B :it talks about bottled water and its result of less on contracting disease [Not bad]
C : Correct diagnosis helped in reducing numbers. [Not bad]

I will take C as B's first sentense is wierdly wordy

krishnasty wrote:The number of people diagnosed as having a certain intestinal disease has dropped significantly in a rural county this year, as compared to last year. Health officials attribute this decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year and thus reduced the incidence of the disease.
Which of the following, if true, would most seriously weaken the health officials' explanation for the lower incidence of the disease?

A) many new water-treatment plants have been built in the last five years in the rural county.
B) Bottled spring water has not been consumed in significantly different quantities by people diagnosed as having the intestinal disease, as compared to people who did not contract the disease.
C) Because of a new diagnostic technique, many people who until this year would have been diagnosed as having the intestinal disease are now correctly diagnosed as suffering from intestinal ulcers.
D) Because of medical advances this year, far fewer people who contract the intestinal disease will develop severe cases of the disease.
E) The water in the rural county was brought up to the sanitary standards of the water in neighboring counties ten years ago.

Covering this up, I'm not clear on whether you are asking for help or just presenting this for the impression of the community.
[spoiler]Most definitely C, as it presents an alternative explanation for the drop in the number of people diagnosed with the disease - it's not that the disease disappeared, as the fact that it was a mis-diagnoses in the first place. [/spoiler]

IMO C. Please fine the reasoning below:

A) many new water-treatment plants have been built in the last five years in the rural county.
irrelevant, it is only talking about when the plant were built

B) Bottled spring water has not been consumed in significantly different quantities by people diagnosed as having the intestinal disease, as compared to people who did not contract the disease.
Irrelevant, it says there was no variation in consumption of bottle spring water by people did not get the disease and those who did. BUT we are talking about water treatment plants

C) Because of a new diagnostic technique, many people who until this year would have been diagnosed as having the intestinal disease are now correctly diagnosed as suffering from intestinal ulcers.
This weaken by saying that water treatment plant were not helpful but earlier there was a wrong diagnosis of a disease and now that flaw is rectified

D) Because of medical advances this year, far fewer people who contract the intestinal disease will develop severe cases of the disease.
This statement is talking about FUTURE

E) The water in the rural county was brought up to the sanitary standards of the water in neighboring counties ten years ago.
Does not weaken the plan of water treatment plants as water treatment plants could be used to raise the standards

two possible paraphrases can be 1. the water from the plants is not being used. 2 the diagnostic technique has changed and as a result the number of people diagnosed with the problem has decreased.

C fits the bill.

Geva@MasterGMAT wrote:

krishnasty wrote:The number of people diagnosed as having a certain intestinal disease has dropped significantly in a rural county this year, as compared to last year. Health officials attribute this decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year and thus reduced the incidence of the disease.
Which of the following, if true, would most seriously weaken the health officials' explanation for the lower incidence of the disease?

A) many new water-treatment plants have been built in the last five years in the rural county.
B) Bottled spring water has not been consumed in significantly different quantities by people diagnosed as having the intestinal disease, as compared to people who did not contract the disease.
C) Because of a new diagnostic technique, many people who until this year would have been diagnosed as having the intestinal disease are now correctly diagnosed as suffering from intestinal ulcers.
D) Because of medical advances this year, far fewer people who contract the intestinal disease will develop severe cases of the disease.
E) The water in the rural county was brought up to the sanitary standards of the water in neighboring counties ten years ago.

Covering this up, I'm not clear on whether you are asking for help or just presenting this for the impression of the community.
[spoiler]Most definitely C, as it presents an alternative explanation for the drop in the number of people diagnosed with the disease - it's not that the disease disappeared, as the fact that it was a mis-diagnoses in the first place. [/spoiler]

OA : C

well, i got the answer correctly but thought of this as an interesting question. Hence, for the benefit of community, i posted this question..i guess it's a good thing..right??

krishnasty wrote:

Geva@MasterGMAT wrote:

krishnasty wrote:The number of people diagnosed as having a certain intestinal disease has dropped significantly in a rural county this year, as compared to last year. Health officials attribute this decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year and thus reduced the incidence of the disease.
Which of the following, if true, would most seriously weaken the health officials' explanation for the lower incidence of the disease?

A) many new water-treatment plants have been built in the last five years in the rural county.
B) Bottled spring water has not been consumed in significantly different quantities by people diagnosed as having the intestinal disease, as compared to people who did not contract the disease.
C) Because of a new diagnostic technique, many people who until this year would have been diagnosed as having the intestinal disease are now correctly diagnosed as suffering from intestinal ulcers.
D) Because of medical advances this year, far fewer people who contract the intestinal disease will develop severe cases of the disease.
E) The water in the rural county was brought up to the sanitary standards of the water in neighboring counties ten years ago.

Covering this up, I'm not clear on whether you are asking for help or just presenting this for the impression of the community.
[spoiler]Most definitely C, as it presents an alternative explanation for the drop in the number of people diagnosed with the disease - it's not that the disease disappeared, as the fact that it was a mis-diagnoses in the first place. [/spoiler]

OA : C

well, i got the answer correctly but thought of this as an interesting question. Hence, for the benefit of community, i posted this question..i guess it's a good thing..right??

By all means - go ahead!

It's just sometimes unclear to us experts whether whoever posted the question wants our help (i.e. post out opinion ASAP) or is good with the question, and just wants to show the community (in which case we might delay our posts to let others have a go first).

I guess that's why we have the spoiler effect.

Geva@MasterGMAT wrote:

krishnasty wrote:

Geva@MasterGMAT wrote:

krishnasty wrote:The number of people diagnosed as having a certain intestinal disease has dropped significantly in a rural county this year, as compared to last year. Health officials attribute this decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year and thus reduced the incidence of the disease.
Which of the following, if true, would most seriously weaken the health officials' explanation for the lower incidence of the disease?

A) many new water-treatment plants have been built in the last five years in the rural county.
B) Bottled spring water has not been consumed in significantly different quantities by people diagnosed as having the intestinal disease, as compared to people who did not contract the disease.
C) Because of a new diagnostic technique, many people who until this year would have been diagnosed as having the intestinal disease are now correctly diagnosed as suffering from intestinal ulcers.
D) Because of medical advances this year, far fewer people who contract the intestinal disease will develop severe cases of the disease.
E) The water in the rural county was brought up to the sanitary standards of the water in neighboring counties ten years ago.

Covering this up, I'm not clear on whether you are asking for help or just presenting this for the impression of the community.
[spoiler]Most definitely C, as it presents an alternative explanation for the drop in the number of people diagnosed with the disease - it's not that the disease disappeared, as the fact that it was a mis-diagnoses in the first place. [/spoiler]

OA : C

well, i got the answer correctly but thought of this as an interesting question. Hence, for the benefit of community, i posted this question..i guess it's a good thing..right??

By all means - go ahead!

It's just sometimes unclear to us experts whether whoever posted the question wants our help (i.e. post out opinion ASAP) or is good with the question, and just wants to show the community (in which case we might delay our posts to let others have a go first).

I guess that's why we have the spoiler effect.

I get you your point..I would remember that from next time..
and thanks once again for helping me other GMAT aspirants