Mark the letter A, B, C or D to indi...

Câu hỏi: Mark the letter A, B, C or D to indicate the sentence that best combines each pair of sentences in the following questions.
Question 29: I'm sorry I wasn't in the office when you phoned. I know I promised to be.

A. I should be in the office when you phoned.

B. I should have been in the office when you phoned.

C. I must have been in the office when you phoned.

D. I might be in the office when you phoned.