A、  B、  C、  A因为是Where~?的问题，所以表示场所的选项是正确答案，(A)虽然使用过去时，但是从“他去了总公司”可以了解到：他现在人在总公司。in charge of是“负责”的意思。

(Woman)Would you recommend the new novel by Paul Miller?
(Man) (A) Well, maybe not to everyone.
(B) On the bookshelf.
(C)I got some good comments from him.

(Man) Where’s the supervisor who’s in charge of this project?
(Woman)(A) He went to the main office for the afternoon.
(B)  In another week or two, at the most.
(C) We charge 30 dollars for this projector.