In Shakespeare's "Sonnet 29," the speaker feels depressed because he wishes he were wealthier, more gifted and prosperous, and that he had more friends. However, his mood changes when he becomes fully aware that his woman loves him. As a result, he feels happier and more enthusiastic.
Out of the choices given, attacking the person instead of the argument is a type of logical fallacy called ad hominem. The correct answer is C, ad hominem.