Critical Reasoning

Cardiologist: Coronary bypass surgery is commonly
performed on patients suffering from coronary
artery disease when certain other therapies would
be as effective. Besides being relatively
inexpensive, these other therapies pose less risk
to the patient since they are less intrusive. Bypass
surgery is especially debatable for single-vessel
disease.
The cardiologist's statements, if true, most strongly
support which one of the following?
(A) Bypass surgery is riskier than all alternative
therapies.
(B) Needless bypass surgery is more common today
than previously.
(C) Bypass surgery should be performed when more
than one vessel is diseased.
(D) Bypass surgery is an especially expensive
therapy when used to treat single-vessel
disease.
(E) Sometimes there are equally effective
alternatives to bypass surgery that involve less risk.

Answer E [spoiler]Why D is not the answer. There is a subtle difference between both the choices. Can somebody please elaborate ?[/spoiler][/spoiler]

pink_08 wrote:Cardiologist: Coronary bypass surgery is commonly
performed on patients suffering from coronary
artery disease when certain other therapies would
be as effective. Besides being relatively
inexpensive, these other therapies pose less risk
to the patient since they are less intrusive. Bypass
surgery is especially debatable for single-vessel
disease.
The cardiologist's statements, if true, most strongly
support which one of the following?
(A) Bypass surgery is riskier than all alternative
therapies.
(B) Needless bypass surgery is more common today
than previously.
(C) Bypass surgery should be performed when more
than one vessel is diseased.
(D) Bypass surgery is an especially expensive
therapy when used to treat single-vessel
disease.
(E) Sometimes there are equally effective
alternatives to bypass surgery that involve less risk.

Answer E [spoiler]Why D is not the answer. There is a subtle difference between both the choices. Can somebody please elaborate ?[/spoiler][/spoiler]

E is far better than D. Look at the bold part, E can be clearly inferred from this.

Is it anywhere mentioned that Bypass surgery is especially expensive to treat single-vessel disease ?? Also from last sentence Bypass surgery is especially debatable for single-vessel disease, but we dont know why. reason may be due to risk factor as well.

Is this similar in some way to

https://www.beatthegmat.com/great-gmatpr ... 35489.html

Well this is a strengthen question and we need to look for answer choice that will support the conclusion .


Conclusion : Bypass surgery is especially debatable for single-vessel disease.

Meaning Bypass surgery is not required in all kind of diseases .

Lets look at the answer options .

(A) Bypass surgery is riskier than all alternative therapies.
[This is a trap answer . Although the passage mentions risk , the conclusion however dose not mention any risk involved , eliminate.]
(B) Needless bypass surgery is more common today than previously.
[Types of bypass surgery is not mentioned , out of scope , eliminate]
(C) Bypass surgery should be performed when more than one vessel is diseased.
[Though the passage says Bypass surgery is debatable that dose not mean bypass surgery should not be performed, may be a contender , lets look at others. ]
(D) Bypass surgery is an especially expensive therapy when used to treat single-vessel disease.
[No where in the passage it is said that bypass surgery will be cost effective when used in cases in which more than one vessel is involved . Debatable may be in terms of cost OR in terms of risk involved we can never be sure. Eliminate ]
(E) Sometimes there are equally effective alternatives to bypass surgery that involve less risk.
[This option is simply restating the conclusion. Sometimes = Bypass surgery is not required in all kind of diseases. This is what the conclusion says but is simply rephrased . Correct.]

Note the part highlighted by Phirozz

certain other therapies would be as effective & pose less risk

and option (E) Sometimes there are equally effective
alternatives to bypass surgery that involve less risk

(E) is not even subtly different from what has been said in the passage, even the word effective is repeated.

If it has already been mentioned in the Argument then how is (E) weakening or strengthening the argument. At best it is reiterating. This is repeated by (A) (B) and (C)
If the conclusion as per rockeyb is Conclusion : Bypass surgery is especially debatable for single-vessel disease.
then (D) Bypass surgery is an especially expensive therapy when used to treat single-vessel disease is my choice.

rockeyb wrote:Well this is a strengthen question and we need to look for answer choice that will support the conclusion .

rockeyb,

we need to look for an option which is supported BY the conclusion, if it is true.

Not the other way round.

The cardiologists' statements, if true, most strongly
support which one of the following?

therefore, it falls in Must-Be-True question type. : )

kstv wrote:If it has already been mentioned in the Argument then how is (E) weakening or strengthening the argument. At best it is reiterating.

as said before, we have to find a statement which is most likely to be true based on the conclusion. Not a strengthener / weakener. You've already said that a clone of E is present in the passage itself. Therefore, it will be the best one to chose!

Thanks again Harsha for correcting me

I agree that D is a contender. However, this is a kind of shell game in terms of power score. Passage says that Bypass surgery is an especially expensive but didn't talks about when? whether single-vessel, double-vessel or multiple (I don't have much idea how many vessels are there. Some doctor can shed some light on this). Because we don't have answer for 'when' question, this is not the right answer.

pink_08 wrote: (D) Bypass surgery is an especially expensive
therapy when used to treat single-vessel
disease.

This is good option. This option is not too extreme, and agrees with the passage.

pink_08 wrote: (E) Sometimes there are equally effective
alternatives to bypass surgery that involve less risk.