I just don’t understand ____that leads to so many teenagers becoming addicted to playing computer games.                                         

A．why it does

B．what it does

C．what it is

D．why it is

下列选项中，（）很可能是婴幼儿产品的潜在客户。

A.高中生

B.未婚女孩

C.怀孕的妇女

D.婴儿的父亲