Mark the letter A, B, C, or D on your answer sheet...

Câu hỏi: Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.
They were travelling on the same train so they_________. But, of course, we don't know if they did.

A. might meet

B. may have met

C. should probably met

D. could meet