It is certain that he will ________ his business to his son when he gets old.

A.take over

B.think over

C.hand over

D.go over

答案及解析： C

take over意为"接管"，hand over意为"移交"；think over意为"仔细考虑"；go over意为"复习"，由题意和短语区别可知选C。