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.
Peter was in a very bad mood. His car had broken down.
A. Peter was in a very bad mood, whose car had broken down.
B. Peter, whose car had broken down, was in a very bad mood.
C. Peter who's car had broken down was in a very bad mood.
D. Peter, who was in a very bad mood, his car had broken down.