Mark the letter A, B, C or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.
I left the office. There was a power cut just then.
A. I left the office after there was a power cut.
B. Hardly I had left the office when there was a power cut.
C. No sooner had I left the office than there was a power cut.
D. I left the office long before there was a power cut.