`Donna: Can you tell me where the library is?
Harry: Of course, it’s behind the teaching building.
Donna: Thanks.
Harry: ________.

`Donna: Can you tell me where the library is?
Harry: Of course, it’s behind the teaching building.
Donna: Thanks.
Harry: ________.

A. Don’t be so sure.

B. I’m happy to have done it.

C. You are welcome.

D. I’m glad you like it.

正确答案是C