Thanks for the question! The question here is asking us for a central purpose of each passage. (E) tells us that this central purpose is to examine the impact of European literature and literary theory on Cather’s work. Let’s first take a look at passage A: passage A, for one thing, doesn’t mention literary theory at all. In addition, the discussion of European literature (Turgenev) did not have the main purpose of examining the impact of Turgenev on Cather’s work, but instead, to show us what Cather’s style was like.
Now let’s take a look at passage B. Passage B doesn’t really discuss the impact of specific European literature on Cather’s work. In addition, the body of literary theory called “narratology” is not discussed for the primary purpose of examining its impact on Cather’s work. Instead, it is brought up as a way of understanding Cather’s work, a framework we can apply to Cather’s work. For this reason, answer choice (E) has to be incorrect. We can see that both passages are simply identifying distinct characteristics of Cather’s work and her literary style, and this is why (B) is the correct answer choice.
Hope this helps! Feel free to ask any other questions that you might have.