The fog comes on little cat feet. it sits looking over harbor and city on silent haunches. and then moves on. which of the following is the main difference between sandburg’s “fog” and frost’s "mending wall"?

a. “fog” uses metaphor, while “mending wall” does not.
b. “fog” uses everyday language, while “mending wall” does not.
c.“mending wall” is in free verse, while “fog” is not.
d. “mending wall” is in a modern format, while “fog” is not.