How does the speaker’s repetition of the neighbor’s cherished belief about the importance of walls (lines 27 and 45) convey the poem’s criticism of an undesirable social pattern?

Iam guessing it’s a metallic because it is powdery and so belongs to group 2it is also light. so i would guess it’s graphite.if available, additional information would be very for-example its color. if black it would be division e. also try to mark it on a paper.

So what is the question

I'm not sure but it could be c ( not a 100% sure )