Mark the letter A, B, C or D on your answer sheet to indicate the sentence that is closet in meaning to each of the following questions.
He delayed writing the book until he had done a lot of research.
A.Only after he had done a lot of research did he begin to write the book.
B.He did a lot of research after he finished writing the book.
C.He delayed writing the book as he had hardly done any research.
D.It was only when he had written the book that he did a lot of research.