A、Nothing. B、Three dollars. C、A few cents. D、Fifty cents. A细节明示题。题目问校园服务车的收费问题。对话中女士提到It’s free,由此我们知道它是免费的，所以答案选A。

M: Can you tell me about the university shuttle bus system? This is such a large campus, and I have classes all over campus. I need to take the shuttle bus from one class to another, or I’ll never make it on time.
W: What do you need to know? I think it’s a really ~eat system.
M: First of all, where does it go?
W: The university shuttle bus system goes all over campus. It doesn’t leave the campus; if you want to travel off-campus, you’ll need to take the city bus system. But the university shuttle bus system will get you from one class to the next very efficiently.
M: And how much does it cost?
W: I’ts free, can you believe it? So you don’t have to pay a cent to get all around the university campus.
M: That’s really great. And how do I catch the shuttle bus?
W: Just look for one of the bright yellow shuttle bus signs, and go sand next to it. You can see the yellow shuffle bus signs all over campus. A shuttle bus will come along approximately every five minutes, so you shouldn’t have to wait long.
M: That sounds good. Thanks for your help.
W: No problem.