问题详情

A: I"d like to have an economy ticket with an open return to Chicago next Monday. B: ______
A．One moment, please. I"ll check if it is available.
B．Just a second. I"ll check the open return schedule.
C．Wait a minute. Why don"t you take the first class？
D．I guess that"s OK. But there is no flight come back.请帮忙给出正确答案和分析，谢谢！