___________, Joe was annoyed to find that he had left...

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.
___________, Joe was annoyed to find that he had left his key at the coffee shop.
A. After returned to his office
B. To have just returned to his office
C. Upon returning to his office
D. Having been returned to his office