A:My dear,-----with you?B:I don't feel well and I'm afraid I

A:My dear,_____with you?B:I don't feel well and I'm afraid I can't go to school today.
A.What's the wrong.
B:What's the matter.
C:What's the trouble.
D:What illness do you have.
哪个正确,并分析一下为什么!