Task: Dialogue Generation
Input (English): F: Good morning, Northwind Airways. May I help you? ,M: Yes, do you have any afternoon flights to Shanghai on July seventh? ,F: One moment please. Yes, there is a flight at 12:45 PM and one at 4:40 PM. ,M: Either of those would be fine. Can you tell me how much a return flight would cost? I'll be returning on July twenty-first.
(A) F: Let me check for you. A return ticket on July 21st from Shanghai, right? (B) F: I am afraid I did not quite catch what you were saying. Please repeat it. (C) F: So you may need a round ticket from July 10th to 21st to and from Beijing. (D) F: Sir, we don't have flight for you to return from Beijing on July 27th. I'm sorry.
Output (English): A