I didn't know you we...

Câu hỏi: I didn't know you were coming, so I didn't wait for you.

A.Were I to know you were coming, I would wait for you. 

B. If I had known you were coming, I would wait for you. 

C. Had I known you were coming, I would have waited for you. 

D. If I knew you were coming, I would wait for you.