Since other choices are useless in my opinion, it is "exaggeration"
The answer is C, they present the problem in the first part of the sentence (rather than...) and provide a solution in the second half.
Romeo calls it a cordial because, the poison will "help heal his heart".
Also cordial means <span>a comforting or pleasant-tasting medicine. So in a sense it is helping him heal, so he can be with Juliet.</span>