" It helps readers to better imagine the motionlessness of the moon in contrast to the movement of the dune grass." "
A) Relocating/subject
A gerund is specifically, a noun made by adding the suffix "-ing" to a verb. In this case the only gerund is "relocating", which means that that must be the correct answer. So, by process of elimination, A is the correct answer.
I think the answer is A. Her taste in food is awkward.
