Weaken questions engage in “inductive reasoning”, meaning the correct answer is allowed to introduce information not contained in the stimulus. It just needs to be reasonably relevant.
“Reasonably relevant” can be understandably irritating for GMAT students - just know that “reasonableness” is a very real US legal standard (its even in the Constitution).
Answer (A) introduces “outside information” in the form of increased tuition. For this answer to be correct, we need to assume the increased tuition translates into fewer students applying. In pure “deductive reasoning” (virtually nonexistent on the GMAT, but common on the LSAT), this assumption wouldn’t fly.
But inductive reasoning allows for what could be called “real world” situations - like how increasing tuition would lead to fewer applicants. That is, it is perfectly reasonable to assume that increase tuition leads to fewer applicants.
But what about D? Introducing other colleges experiences might very well be relevant. But not in this case because the other colleges’ experiences demonstrate they failed to increase their visibility, which is NOT the issue/reasoning supporting the original conclusion.
WHY is the conclusion of this argument true? That is, why will the college increase their “student count?” Because more students will apply. Period.
Any information supporting the evidence/premises is irrelevant. WHY is the evidence true? That is, WHY will more students apply? Because visibility will be increased.
Everyone knows that evidence/premises from an argument is assumed to be true. This means that anything that supports this evidence must be irrelevant. We don’t care why it’s true, because we assume it’s true.
Answer D indicates that other colleges were unable to increase visibility after increasing its research. We don’t care about other colleges unable to increase their visibility - the argument has already established as truth that for Trinity college specifically, increased research will lead to increased visibility.
On a separate note: this seems to be a non-official question (I tried looking it up, please correct me if I’m wrong). Recall that official verbal questions are essentially written by committee, with data-driven revisions not available to anyone else. This makes strict analysis of expert written questions a little bit tricky.
This one was awesome, though. The writer clearly knows his or her logic.
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