A、  B、  C、  C提问人数(How many)的问题，所以回答four的选项(C)为正确答案。(A)中Yes／No类的回答是不正确的，(B)是针对When提问时的回答。

Do you think Alex is ready for the promotion?
(A) I think the title was Associate Director of Marketing.
(B) Definitely, he already takes on most of the duties.
(C) I’m ready for more responsibility, but no one ever gives me the opportunity.

How many representatives did they send?
(A) Yes, they’re here.
(B) They sent it on Monday.
(C) Four, including Mr. Flynn.