【正确答案】 D

【答案解析】原文：W：Youth Travel Agency! What can I do for you, sir?M：I’ve read your advertisement about the tour to China. I am calling to inquire about it.Q：What does the man want to know?题干问男士想要知道什么。通过对话内容可知，男士想要知道关于去中国旅行的信息。故选D。