Martin: Can you cover for me on Sunday? Im supposed to teach the high school class. Lisa: Sure. ___

Martin: Can you cover for me on Sunday? I'm supposed to teach the high school class. Lisa: Sure. ______ ? Martin: We're going to the beach for the weekend. Lisa: Well, don't worry. I'll take good care of Sunday school.

A．What's in

B．What's the thing

C．What's up

D．What's down