I believe F. Scott Fitzgerald wanted to portray Gatsby as a human. When someone is so royally popular, wealthy, and successful it can be hard to see them as anything but those superficial, materialistic things. Gatsby is shown trying to "fit in" so to speak, choosing his words wisely, yet amidst his attempts at formality, he still can't fit the mold that he so desires to conform to.
Im pretty sure it is personification because its giving the grapevines a human action.
The answer is D I believe.
