F: Excuse me, could I ask you some questions? ,M: Of course.
(A) F: I’m sorry, I don’t understand. Could you say it again? (B) F: Oh, you don't have time for my survey. That's OK. (C) F: Thank you. I want to ask you some questions for my survey. (D) F: Thank you for visiting our travel agency. Here is an advertisement.
C