我国古代思想家王充所说的"施用累能"是指（）。

A.学校教育对智力的影响

B.社会实践对智力的影响

C.遗传对智力的影响

D.家庭环境对智力的影响

One day a car rental agency rented 2/3 of its cars, including 3/5 of its cars with CD players. If 3/4 of its cars have CD players, what percent of the cars that were not rented had CD players ？（）

A. 10%

B. 35%

C. 45%

D. 66.7%

E. 90%