【正确答案】 C

【答案解析】原文：M: I had an appointment with Dr. Smith this afternoon and I need to change it to tomorrow morning. W: Let me check. Tomorrow morning...no problem. Q: When does the man want to see Dr. Smith?题干问的是"男士为什么想换工作"。根据对话内容，男士之所以想换工作是因为公司要搬去上海而他想留在广州，故选C。