I DID NOT ANSWER THE DOOR EVEN THOUGH I KNEW IT WAS MY FRIEND

15. I did not answer the door even though I knew it was my friend.A. unless I knew it was my friend, I would not answer the door.B. I knew it was my friend, but I did not answer the door.C. Only when I answered the door did I knew it was my friend.D. I answered the door since I knew it was my friend.