Task: Dialogue Generation
Input (English): M: I'd like to rent a bike for a day. How much does it cost? ,F: It's $20 a day. A day is from 9 o'clock in the morning until 7 o'clock in the evening. ,M: So if I brought the bike back at 7:30, would I have to pay for an extra day? ,F: Yes, and there's a deposit to pay as well. It's $50. Then when you bring the bike back, we'll give you back the $50. But if you didn't bring the bike back before 7:00 PM, we'd keep the money of course. ,M: Well. You don't need to worry. I'll surely bring the bike back at 5 o'clock. Do you have helmets, by the way? ,F: Of course. It's free to rent a helmet. Let's go and choose a bike and helmet for you.
(A) M: Really? It's expensive to rent a helmet? And if I bring the bike back after 7:00 pm, I have to pay for the helmet? (B) M: Really? You mean you have no helmet? And if  I bring the bike back after 7:00 pm, I have to pay 100 dollars more? (C) M: OK, I see. You mean it's free to rent a helmet. But if  I bring the bike back after 7:00 pm, I cannot get the 50 dollars back. (D) M: I am afraid I did not quite catch what you were saying. Please repeat it.
Output (English): C