A、  B、  C、  A问题是一个反意疑问句，为确认前面叙述的内容。问的是她是不是去看游行了，(A)并未表示肯定或否定，而是回答说不知道，因此是最合适的答案。

Why is the client so upset?
(A) Perhaps, but I don’t have the time.
(B) He doesn’t like our suggestions.
(C) They’ve climbed it by now, I think.

She went to see the parade yesterday, didn’t she?
(A) I really don’t know.
(B) Alright, if you insist.
(C) No, I haven’t seen her for a while.