B
A is off right away because that is the first definition of document. Although b and c are both verbs, b simply makes more sense and is the obvious answer.
The activity which is a way for students to make a positive digital footprint is the A. Blog posts.
D. A and B are obvious because sue does not equal we and dancers does not equal her. C caught me, but windowS does not equal it (which is singular). The only answer left is D.
