A、Sports shoes. B、Sun glasses. C、A sun hat. D、A T-shirt. B问题问的是“男士想要买什么?”根据第一句可知，他想买太阳眼镜。故选B。

M: May I have a look at this pair of sun glasses?
W: Sure. Here you are.
M: How much does it cost？
W: It’s $300.
M: Oh, it’s a bit too expensive.
W: We can offer you a discount since you are a regular customer.
M: So how much exactly should pay you?
W: $240.
M: How about 200?
W: All right.
17. What does the man want to buy?
18. Why does the woman offer the man a discount?
19. How much does the man pay in the end?