The correct answer is D. The lack of punctuation. It makes the poem sound as if it were a single, swift, concise, and laconic sentence. It also give the poem a conversational tone, depriving it of artificiality that was a characteristic of the pre-20th-century poetry. Punctuation would fragmentise the poem and induce its flow with pauses.
I believe it is the closing cause in interviews the interviewer is trying to get the juicy stuff so the beginning is juicy then body is juicier then the closing should be the juiciest