I did not see Susan off at the airport. I feel bad...

Câu hỏi: I did not see Susan off at the airport. I feel bad about it now.

A I could have seen Susan off at the airport.

B If only I had seen Susan off at the airport.

C That I did not see Susan off at the airport escapes me now.

D It suddenly dawns on me that I should have seen Susan off at the airport.