A、  B、  C、  C疑问词(Which)开始的疑问句小能用Yes／No来回答，因此(A)项就被排除了。题干问的是需要什么样的文件夹，(C)项的回答具体说明了是最上面抽屉里的The AstraFile，因此是正确答案。

You’re finished with the newspaper, right?
(A)It ended last month.
(B)I just ordered a subscription.
(C)Yes, you can take it if you like.

Which file do you need?
(A)Yes, but a little later.
(B)I needed it, but I can wait.
(C)The Astra File in the top drawer.