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.

M: I've been waiting for 3 weeks for someone to return Harry Potter to the library. I'm getting so impatient. ,F: Why don't you just buy your own copy online?
(A) M: You are right. I will buy a book online. (B) M: All right. I will return a book to the library, if someone return Harry Potter to me. (C) M: I am afraid I did not quite catch what you were saying. Please repeat it. (D) M: I don't think so. I still want to borrow a book. But I don't have patience to wait for that.
Output:
D