A、  B、  C、  A问题以疑问词why开头，询问某表演延期的原因。(A)回答说因为主要的客人还没到，因此是正确答案。因为以疑问词开头的问句都不能直接用yes或no来回答，因此(B)用sure回答也是错误的。

Where do you want me to deliver this package?
(A) At 2 o’clock, if possible.
(B) Right here. Thanks.
(C) By evening, I promise.

Why is the show delayed?
(A) The main guest hasn’t arrived.
(B) Sure, it will begin soon.
(C) You can show it to me, right away.