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 didn’t know that you were at home. I didn’t drop in.
A. Not knowing that you were at home, but I still dropped in
B. I didn’t know you were at home although I didn’t drop in
C. Not knowing that you were at home, I didn’t drop in
D. If I knew that you were at home, I would drop in