"Oversimplified" was the keyword.

I took answer choice D wording with "many" to mean "some" and decided it wasn't strong enough, in which case I chose B. Incredibly irritating.

most difficult section is LR for me as well as finishing with answering all questions.

E is irrelevant. You can't prove that the "most frequent relation between opera and stage direction is [...] when stage direction is carried out". That is what E is irrelevant because it doesn't matter. In comparison to answer choice D, it is much more provable than E. Also, you have to refer to the comment about critics stating that "stage direction is never reflected", while the author's stance is that it is reflected. Thus, answer choice D not only reflects the author's stance in the argument but completely blows up the critic's argument and it's provable enough to support the rest of the argument in the stimulus.

I choose B, and realized only after that Answer choice B is too strong. Answer choice A is far more provable.