A、because she gets a student discount B、because Bob doesn’t have very much money C、because she lost a bet and owes Bob money D、b

M: Hey, Allen, how are you?
W: I’m fine Bob. Aren’t you glad the semester is over?
M: Yes, are you going to go to the rock concert Friday night?
W: I haven’t thought much about it, and you?
M: Sure, would you like to go with me?
W: Sounds like fun!
M: You have to buy your own ticket, though.
W: Are you broke again? Let me treat you.
M: Wow, where did you come into so rich cash?
W: You know I am a waitress at the student center. Anyway, now that annual exams are almost over, I’d like a night out.
M: Since you’ve been worried about buying the tickets, why don’t you take us out to dinner?
W: You’ve got a deal. Let’s buy the tickets now.