F: What do you know about Einstein's childhood? ,M: He studied the violin between the age of 6 and 13.
(A) F: I am sorry. You spoke so rapidly that I did not catch the meaning of what you said. Could you repeat that? (B) F: That's what I heard too. Einstein started to learn violin at the age of 13. (C) F: How did you know that Einstein start to learn piano at the age of 6 and 13? (D) F: That's quite young at the age of 6 and 13 to learn violin. But how did you know that?
D