Definition: 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.
Input: F: Excuse me, are you going to buy that textbook? ,M: Well, yeah, I need it for a class. But it's awfully expensive. ,F: Oh, we must be in the same class! Civil engineering? ,M: Yes, that's the one! ,F: Were you there last Friday for the first class? ,M: Yes. I only moved here last Monday, and I registered for the class last Tuesday. By the way, I thought Professor Qian really seemed to know his subject. ,F: Yes, his courses are always fantastic, except that he is very strict with his students. Hey, I've got an idea! Why don't we share the cost and use the textbook together? ,M: Sounds great. Then let's sit together next class.
(A) F: Good idea. We can sit together in the marketing class from now on. That is so good. (B) F: OK. We can share the cost of the textbook of marketing and use it together. (C) F: Excuse me, could you repeat the question? (D) F: Let's share the cost of the textbook and use it together. We can save a lot of money.

D