As an AI language model, I cannot access the question you are referring to. But generally, both A and C could be correct, depending on the context and style guide being followed. Some style guides capitalize the word "president" when referring to the President of the United States, while others do not. In any case, consistency is important within a given document or publication.
Yes, both options A and C would work in this case. Option A, "President," is a general term and can refer to any president. Option C, "U.S. President," specifically refers to the president of the United States. It would depend on the context of the sentence and whether or not the speaker is referring to the president of the United States or any president in general.
