正确答案：
C
解析：
对话中提到了三种交通方式：长途汽车49.50 pounds，往返99.0 pounds；火车59.40 pounds，往返118.80 pounds；飞机往返55 pounds，所以最省钱的是坐飞机。
【录音原文】
W: Can I help you?
M: Yes, I want to get to London. Is it cheaper by coach or by train?
W: That all depends when you want to go.
M: Ok, well, I want to be there by 6 p.m. on Wednesday and be back here by the same time on Tuesday.
W: All right, um…the coach will cost 49.50 pounds for midweek travel and the train is 59.40 pounds.
M: How long does the coach take?
W: Twice as long as the train. But I think I've got a better solution.
M: Yes?
W: Yes. Easy Airlines have the special fare this month. You can get flights to London and back for 55 pounds.
M: All right. Can I book that with you now?
Q: The man wants to get to London. Which is the cheapest way to travel?
