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.
Our flight was delayed. We decided to take a long walk around the terminal.
A.We have been walking around the terminal for a long time since the delay of our flight.
B.We decided to take a long walk around the terminal in case our flight was delayed.
C.Since our flight was delayed, we decided to take a long walk around the terminal.
D.We have been taking a long walk around the terminal since our flight was delayed.