Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.
We were walking in the park when it suddenly poured down.
A.Although it rained heavily, we were walking in the park.
B.The rain suddenly came when we were walking in the park.
C.Walking in the park, it rained heavily.
D.We were walking in the park while it was raining heavily.