A、  B、  C、  C所给出的问题是询问原因(Why)的疑问句。因此选项(C)用because作为回答是最恰当的。要注意虽然问题中出现了early，但本题并不是与时间有关的对话，不要因此而误选选项(A)。

Would you rather look for a jacket at the mall or order one online?
(A) Let’s wait in line.
(B) I didn’t see Jack there.
(C) I’ll look at the mall first.

Why are we getting paid early?
(A) Not until tomorrow.
(B) O.K., I’ll check on them.
(C) Because Friday is a holiday.