A、By 8:30 a.m. B、By 9:30 a.m. C、By 10:00 a.m. D、By 10:30 a.m. B女士说Henry先生现在不在，并问是否需要转告消息；男士说Henry先生的航班是上午10：30起飞，但他必须至少提前一个小时到机场

W: Good afternoon! I’m calling to ask about the apartment you advertised in the newspaper.
M: I’m sorry. But it has already been sold.
Q: What do we know about the apartment?

W: Mr. Henry is not in at the moment. Can I take a message?
M: OK. His flight leaves at 10:30 a. m. But he must be there at least one hour ahead.
Q: When will Mr. Henry have to be at the airport?