This question is for you not for other people. You're the one with memories, this is personal information about you. No one online can help you answer that. This is one from you.
Answer:
c
Explanation:
By beginning the sentence with a similar phrase
In this poem, Pound is comparing "faces in the crowd" to petals that are laying against a tree branch.
This is exactly what he says in the poem - "petals on a wet, black bough." A bough is the main branch of a tree, so this is definitely the only appropriate answer in this case. He wants to say that people resemble these petals.