VI. Choose the sentence which has the closest meaning to the original one.
I did not understand what the lecturer was saying because I had not read his book.
A.What the lecturer wrote and said was too difficult for me to understand.
B.The lecturer's book which I had not read was difficult to understand.
C.I found it very difficult to understand what the lecturer said in his book.
D.I would have understood what the lecturer was saying if I had read his book.