Bramon.Elizabeth!
I don’t agree with your subsuming theory! This theory implies that more than one answer choice is correct, but one answer choice is so hugely correct that it eats up the other correct-ish answer choices. However, with very few exceptions, there is only one right answer choice. The other four are wrong, wrong, wrong, and wrong.
When choosing between two tempting answer choices, don’t compare them to each other. Rather, compare each answer choice to the text (in RC) or to the stimulus (in LR). Practice articulating what makes wrong answers wrong (is it an issue of degree? of scope? of interpretation?) to build your wrong-answer-choice eliminating muscles.
Now to this question:
This question asks, essentially, WHY the author chooses to reference specific poems in the second paragraph. Consider the function of the second paragraph as a whole to understand the function of its parts. The author spends the whole second paragraph describing critical reactions to Cullen’s work. He cites specific poems in the context of analyzing critics’ arguments. Therefore, the poems are intended to add detail to the author’s description of the critics’ claims.
(B) states exactly this, and is correct.
(E) Line 25 describes how certain poems exemplify themes in Cullen’s work. However_ and this is tricky_ the author doesn’t cite the poems to illustrate these themes. Rather, the author cites them to illustrate the claim that "Other [critics] have found Cullen’s use of European verse forms and techniques unsuited to treating political or racial themes." The poems actually function to flesh out the critics’ arguments, not as a digression into the subject of poetic themes.
(C) is similar to (E). Lines 30-33 describe a critic’s complaint that Cullen’s poetic persona vacillates from poem to poem. The poems cited indeed reflect a poet who took on various voices. However, the poems function to illustrate the critics’ argument, not Cullens’ poetic persona.
(A) is out of scope. This paragraph doesn’t concern success.
(D) is unsupported. Again, the paragraph is about the critics’ claims, not the scope of Cullens’ thoughts on poetry.