【正确答案】 C

【答案解析】原文：M：Excuse me. When does flight 645 leave?W：Actually, it is delayed until 15:30.Q：What do we know about the flight?问题问的是“如果游客想在校园内停车,应该怎么做”。通过对话内容可知，男士说游客们应该购买参观许可证,故选C。