This is one of those frustratingly subjective questions where you have to discern the intentions behind the researcher's statement. However, as in all of these seemingly subjective questions, there is a clear right answer.

Remember that the researcher gave a "somewhat offbeat compliment" by comparing physicians to placebos. The researcher is stating that even if the physician doesn't actually do anything to help a patient's physical condition, they might still improve, thinking that physicians can cure anything and are never wrong!

(A) This might be true if the doctor wanted to be a good placebo, but was not the intention of the researcher's comment. The comment was a compliment, a statement, not a proscription about what physicians should do.

(B) Boom, the perfect answer. If physicians are like placebos, then a patient can improve just by knowing they're being cared for by a professional, no matter what the physician actually does.

(C) This might be true, but it is not a compliment of any sort.

(D) Again, this might be a true implication of the researcher's comment, but it is not the general intention. Choice B explains the reasoning behind why this choice might be true, and is thus a much much better answer.

(E) Like C, this is is no possible way a compliment.