【正确答案】 B

【答案解析】[听力原文]
   M: I am tired of working and need a change. So I'm just making plans to go away during Spring Festival.
   W: Really? Where are you going?
   M: I'm planning to visit Tibet.
   W: My brother and I had a vacation there last year and we had a great time.
   M: Did you get into Lhasa?
   W: Sure. That's the first stop. No one should miss Lhasa.
   M: Is the Potala Palace magnificent?
   W: You bet. And don't forget the Barkhor Street. That place is full of treasures, I mean, all the exotic paintings and handicrafts, and the hand-made jewelry.
   M: Well, as there is so much there waiting for me, I guess I should stay longer.
   W: Definitely.
   M: I heard that the weather there is great.
   W: Well, that depends on how you define "great." No humidity, but it could be extremely cold in winter. Besides, you need to be careful about high altitude.
   M: What should I do about that?
   W: Oh, just take it easy for a few days. Don't exercise too vigorously. Just do everything gradually.
   M: I'm sure I will be fine. And I will let you know all about my trip when I come back.
   What's the main purpose of the man's trip?
选项均以“To+原形动词”开头，这表明本题考查行为目的。对话开头男士抱怨自己对现在的工作非常烦，想改变一下，决定去西藏旅游，所以他去西藏的主要目的是放松一下，故答案选B。