15. -Susan married Jason last Sunday.　

-Really? How long _____ each other? No more than a week, I’m afraid.

　 A. did they know　　 　　　　　　　　　　　　　　　　　　　　　　　　 B. have they known　 　

C. have they got to know　　　　　　　　　　　　　　　　　　　 D. had they known