单项选择题

M: How is your job doing, Jane
W: Great! I’m enjoying it a lot. The restaurant is really busy, and the tips are pretty good.
M: I should come and have dinner sometime.
W: Yes, why don’t you I will always welcome an old classmate. You will enjoy our food. I think it’s best.
M: OK! I will go tomorrow.

What is most probably their relationship()

A. They are friends.
B. They are classmates.
C. They used to be colleagues.