italian7745 wrote:Dr. A: The new influenza vaccine is useless at best and possibly dangerous. I would never use it on a patient.

Dr. B: But three studies published in the Journal of Medical Associates have rated that vaccine as unusually effective.

Dr. A: The studies must have been faulty because the vaccine is worthless.

In which of the following is the reasoning most similar to that of Dr. A?

(A) Three of my patients have been harmed by that vaccine during the past three weeks, so the vaccine is unsafe.

(B) Jerrold Jersey recommends this milk, and I don't trust Jerrold Jersey, so I won't buy this milk.

(C) Wingzz tennis balls perform best because they are far more effective than any other tennis balls.

(D) I'm buying Vim Vitamins. Doctors recommend them more often than they recommend any other vitamins, so Vim Vitamins must be good.

(E) Since University of Muldoon graduates score about 20 percent higher than average on the GMAT, Sheila Lee, a University of Muldoon graduate, will score about 20 percent higher than average when she takes the GMAT.

Testluv wrote:

italian7745 wrote:Dr. A: The new influenza vaccine is useless at best and possibly dangerous. I would never use it on a patient.

Dr. B: But three studies published in the Journal of Medical Associates have rated that vaccine as unusually effective.

Dr. A: The studies must have been faulty because the vaccine is worthless.

In which of the following is the reasoning most similar to that of Dr. A?

(A) Three of my patients have been harmed by that vaccine during the past three weeks, so the vaccine is unsafe.

(B) Jerrold Jersey recommends this milk, and I don't trust Jerrold Jersey, so I won't buy this milk.

(C) Wingzz tennis balls perform best because they are far more effective than any other tennis balls.

(D) I'm buying Vim Vitamins. Doctors recommend them more often than they recommend any other vitamins, so Vim Vitamins must be good.

(E) Since University of Muldoon graduates score about 20 percent higher than average on the GMAT, Sheila Lee, a University of Muldoon graduate, will score about 20 percent higher than average when she takes the GMAT.

Hi Italian 7745,

Dr. A's argument is classical circular reasoning: the evidence (that the vaccine is worthless) is the same as his conclusion (vaccine is useless). In this context, "worthless," and "useless" are the same.
Choice C matches this: The conclusion here is that these balls perform the best. The evidence is that they are most effective. This is the same thing.
Choose C.
Let me know if a particular answer choice was bothering you.
As an aside, this is a parallel reasoning question, which is a staple question on the LSAT. I don't think I've ever seen an official GMAT question that was parallel reasoning. In other words, probably wasting your time studying this kind of question.

(Accidentally hit the thanks button instead of the quote button!)