CR- Method of reasoning

vishalwin wrote:Jane: Professor Harper’s ideas for modifying the
design of guitars are of no value because there
is no general agreement among musicians as to
what a guitar should sound like and,
consequently, no widely accepted basis for
evaluating the merits of a guitar’s sound.
Mark: What’s more, Harper’s ideas have had enough
time to be adopted if they really resulted in
superior sound. It took only ten years for the
Torres design for guitars to be almost
universally adopted because of the
improvement it makes in tonal quality.

Which one of the following most accurately
describes the relationship between Jane’s argument
and Mark’s argument?

The thing that jumps out from the juxtaposition of these two arguments is that they don't match. Jane's argument is based on the idea that there is no general agreement about what a guitar should sound like and so no way to evaluate the merits of a design, while Mark's is partly based on the idea that universal adoption, which essentially is an indicator of universal agreement, does indicate merit.

While we'll have to see whether being aware of that issue helps us get the answer, this difference between the arguments is possibly the relationship the question is asking for. Now to see what the answer choices say.

(A) Mark’s argument shows how a weakness in
Jane’s argument can be overcome.

This is tempting, because maybe Jane's premise, that there is no way to determine merit, could be seen as a weakness that is overcome by what Mark says about universal acceptance. At the same time it's not clear that that is actually a weakness of Jane's argument and that what Mark says is actually showing how it could be overcome. I guess keep this for now and continue through the choices.

(B) Mark’s argument has a premise in common
with Jane’s argument.

Actually their premises are quite different, as discussed above.

(C) Mark and Jane use similar techniques to argue
for different conclusions.

Actually they are using different techniques to argue for what is basically the same conclusion, that Professor Harper's ideas do not have value.

(D) Mark’s argument restates Jane’s argument in
other terms.

While he is arguing for basically the same conclusion, his way of getting to that conclusion is different from Jane's and does not restate it.

(E) Mark’s argument and Jane’s argument are
based on conflicting suppositions

Mark's argument is based on the supposition that value can be determined via seeing what guitarists in general do, while Jane is saying that there is no general agreement that can be used to evaluate the merits of a guitar's sound. These conflict with each other, and so this answer choice is a clear winner that matches better than does choice A, our other possibility, what is going on in the prompt.

So the correct answer is E.