choose the answer:

And on a day we meet to walk the line
And set the wall between us once again.
We keep the wall between us as we go.
To each the boulders that have fallen to each.

which line helps develop the idea that walls prevent people from helping each other?

a) And on a day we meet to walk the line

b) And set the wall between us once again.

c) We keep the wall between us as we go.

d) To each the boulders that have fallen to each.