Task: Dialogue Generation
Input (English): F: Shelly has gone to America on holiday. I do envy him. ,M: Really? If so I want to ask him to get something for me. Can I phone him now? ,F: No, you can't because it's after midnight in America. ,M: It's a pity.
(A) F: I mean I really want to call him. (B) F: So he must be sleeping. You can call him hours later. (C) F: I’m sorry, I don’t understand. Could you say it again? (D) F: He's been tired doing projects and must been sleeping now. Don't wake him up.
Output (English): B