Exposure to certain chemicals commonly used in elementary sc

[aspirant2011]

Exposure to certain chemicals commonly used in elementary schools as cleaners or pesticides causes allergic reactions in some children. Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years. Therefore, either Renston's schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago. Which of the following is an assumption on which the argument depends?

A. The number of school nurses employed by Renston's elementary schools has not decreased over the past ten years.
B. Children who are allergic to the chemicals are no more likely than other children to have allergies to other substances.
C. Children who have allergic reactions to the chemicals are not more likely to be sent to a school nurse now than they were ten years ago.
D. The chemicals are not commonly used as cleaners or pesticides in houses and apartment buildings in Renston.
E. Children attending elementary school do not make up a larger proportion of Renston's population now than they did ten years ago.

[spoiler]OA: Will be posted later. Please discuss each answer choice in detail.[/spoiler]

[HSPA]

I am with A.. though C and E are good contenders

A>C>E

Again on negation A has no impact on the conclusion.. it must be C.

Thanks for the assumption questions aspirant..

[aspirant2011]

OA is C ............but I am totally not able to understand how it can be C .............please explain

[mundasingh123]

hi whats the source ?

[aspirant2011]

source is sandeep gupta (ivy GMAT preparation)...........

[ajaarik]

I selected C when I first read the answers.
However, A,C and E are equal contenders.

Any concrete reasons why A and E can be eliminated.

[sourabh33]

+1 for C

Option A - After Negating - no of nurses has decreased over past 10 yrs.
Now in the stem, the author says "the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years"

So even if the no of nurses reduces the proportion should remain same, although actual no of cases may increase (Assuming other non allergic cases not to decrease drastically)

Option E - Out of scope.
The conclusion says - Therefore, either Renston's schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago

[nikit]

Can anyone please explain how 'C' can conclusively be inferred as the most appropriate option?

[Testluv]

Can anyone please explain how 'C' can conclusively be inferred as the most appropriate option?

More and more kids are coming to the nurses office. The author argues that this can only be explained by greater exposure or greater sensitivity. So, he must be assuming that there aren't any other explanations.

Choice C clearly defends the argument against an alternative explanation. Use the Kaplan denial test:

If kids ARE more likely to be sent to the nurses office than before, then it is not necessarily the case that there is more exposure or more sensitivity.

Choice A is tempting because it also seems to defend the argument against an alternative explanation; after all, if there are fewer nurses, then each nurse would naturally be seeing more kids. However, the key is that "Elementary school nurses in Renston" are a group. And as a group they are reporting an increase in kids sent to them for these allergic reactions.

[aspirant2011]

Can anyone please explain how 'C' can conclusively be inferred as the most appropriate option?

More and more kids are coming to the nurses office. The author argues that this can only be explained by greater exposure or greater sensitivity. So, he must be assuming that there aren't any other explanations.

Choice C clearly defends the argument against an alternative explanation. Use the Kaplan denial test:

If kids ARE more likely to be sent to the nurses office than before, then it is not necessarily the case that there is more exposure or more sensitivity.

Choice A is tempting because it also seems to defend the argument against an alternative explanation; after all, if there are fewer nurses, then each nurse would naturally be seeing more kids. However, the key is that "Elementary school nurses in Renston" are a group. And as a group they are reporting an increase in kids sent to them for these allergic reactions.

Hi Testluv,

In option C "Children who have allergic reactions to the chemicals" over here to which is "chemicals" refering to?????Is it refering to the chemicals mentioned in the first line of the argument i.e to "cleaners or pesticides"????????

[Testluv]

Hi aspirant2011,

yes. Since choice C talks about "the chemicals" and since there is only one group of chemicals the arguer considers, it must be the same group of chemicals that the stimulus discusses.

[aspirant2011]

Hi aspirant2011,

yes. Since choice C talks about "the chemicals" and since there is only one group of chemicals the arguer considers, it must be the same group of chemicals that the stimulus discusses.

Hi Testluv,

The thing which is making me confused in this particular CR is that If I use the negation technique then option C becomes-

Children who have allergic reactions to the chemicals (i.e cleaners or pesticides) are more likely to be sent to a school nurse now than they were ten years ago.

Then how is above negated option weakening my conclusion i.e

Therefore, either Renston's schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago.

I am really weak in CR part ........please help me out[/i]

[sk8legend408]

Hi aspirant2011,

Actually what choice C means is that children currently are more likely to go to the nurse if they have an allergic reaction than ten years ago. As in ten years ago even if a child had an allergic reaction he/she may not have been sent because allergic reactions were not perceived so seriously as they are now.

Hope that helps.

[chufus]

Can anyone please explain how 'C' can conclusively be inferred as the most appropriate option?

More and more kids are coming to the nurses office. The author argues that this can only be explained by greater exposure or greater sensitivity. So, he must be assuming that there aren't any other explanations.

Choice C clearly defends the argument against an alternative explanation. Use the Kaplan denial test:

If kids ARE more likely to be sent to the nurses office than before, then it is not necessarily the case that there is more exposure or more sensitivity.

Choice A is tempting because it also seems to defend the argument against an alternative explanation; after all, if there are fewer nurses, then each nurse would naturally be seeing more kids. However, the key is that "Elementary school nurses in Renston" are a group. And as a group they are reporting an increase in kids sent to them for these allergic reactions.

I think Choice A is never tempting because the argument explicitly says "Proportion of Children", that means the number of school children and the number of nurses does not matter at all. And hence C becomes a clear winner. Just an observation. The key always lies in the use of certain "Key Words", if you may, and these key words generally will lead you to the right answer. The answer is always in the argument....

[karthikgmat]

The conclusion is Therefore, either Renston's schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago. , So the assumption would be lying on children exposed to chemicals . From the options A , C are possible. After you negate A, it doesnt attack the argument." simply A doesnt even talk about children, eliminate. E is out of scope, as it was saying about renston's population

so IMO C.