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.
He was successful in his career thanks to his parents' support.
A. But for his parents' support, he wouldn't have been successful in his career.
B. If his parents hadn't supported him, he would have been successful in his career.
C. Had it not been for his parents' support, he wouldn't be successful in his career.
D. Had his parents supported him, he wouldn't be successful in his career.