Enjambment refers to the incomplete syntax at the end of the line, which means that the sentences run from one line of poetry to the next, without terminal punctuation (period). Lines that are not enjambed are called "end-stopped." Enjambment serves to increase tension as the meaning is delayed until the sentences are completed.
I know the answer isn't C or D. A or B both seem likely until you see that B involves a 'comma without a conjunction,' either way you should never put a comma before 'and'; I am not sure why but I am pretty sure this only applies in a formal document. So your answer is A.
