Explanation
A. (Correct Response) Passage B discusses the difficulty of defining genres and mentions "borderline cases"—works that do not fit neatly within a genre's definition, which could be those not written to exploit a specific reading protocol.
B. Passage B implies that readers' expectations, or "reading protocols," which could involve expectations about a genre, play a significant role in how a work is classified.
C. The passage suggests that thematic similarities are not the most useful basis for genre demarcation since the definition often fails due to "borderline cases."
D. Passage B does not make a specific claim about the interpretation of a sentence in fiction being independent of genre.
E. This is contrary to what Passage B argues; it suggests that not all works that are classified within a genre will strictly adhere to the same themes or content elements due to the problem of "borderline cases."