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.
John speaks Chinese fluently because he used to live in China for ten years
A. Suppose John has lived in China for ten years, he can speak Chinese fluently
B. Provided that John lived in China for ten years, he could speak Chinese fluently
C. Unless John had lived in China for ten years, he could not have spoken Chinese fluently
D. John could not speak Chinese fluently if he had not lived in China for ten years.