You will be given a definition of a task first, then some input of the task.
In this task you are given a small conversation between two persons and 4 options on how the conversation should continue. Your job is to choose the most reasonable option. The conversation and the options are separated by a newline character. Each dialogue in the conversation are separated by a comma. F and M indicate female and male, respectively.

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. ,F: Economy, business, or first class? ,M: Economy, please. ,F: OK, that will be $500. Which afternoon flight would you like to take on July seventh? ,M: The 441.
(A) F: No problem. A first class for your return flight, 500 dollars. (B) F: I've booked business class for your return flight on the 28th. (C) F: I am sorry. You spoke so rapidly that I did not catch the meaning of what you said. Could you repeat that? (D) F: Economy class for flights to and from Shanghai. $500 in total.
Output:
C