单项选择题

M: Have you seen my school bag, Mom I’ve been looking for it everywhere.
W: I hope you didn’t leave it in school. You never know where you put your things. Where did you last see it
M: Last night before I went to bed, I think. I remember putting it on the desk
W: Really If you put it there, it should still be there. No one has been to your room. So it must be here somewhere.
M: Yes, but where That’s what I want to know. Oh, dear, it’s about the time for the school bus.
W: Hey, what’s that under your blanket at the foot of your bed

What is the relationship between the two speakers()

A. They are brother and sister.
B. They are mother and son.
C. They are husband and wife