F: Mister Williams, these days, David has been looking tired all the time. He has been falling asleep in class. I wonder if you should take him to see a doctor. ,M: Thanks, Miss Jones. I know what the problem is. He's recently been going to bed far too late. ,F: When does he go to bed? ,M: Usually around 11 o'clock. Sometimes even later.
(A) F: It's too late to go to bed at nine. (B) F: I didn’t hear you. Please could you tell me again? (C) F: It's too late to go to bed at eleven. (D) F: You can't let him sleep eleven hours a day.
C