【单选题】

Man: These family reunions are complicated. Could you pick Mark up from the airport I'm on a tight schedule today.Woman: OK, but then let's switch. I'm supposed to pick Sarah up tomorrow.Question: What does the woman mean
A．Mark won't be able to come to the reunion.

B．She'd rather pick up Sarah.
C．She'll go to the airport today instead of tomorrow.
D．She thought Mark would be arriving tomorrow.