In some countries,_____ are called "public schools" are not owned by the state.

A．that

B．which

C．as

D．what

在美国，由政府管理的用于支付退休收益的基金称为（）养老基金。

A.公司养老基金

B.社会养老基金

C.私人养老基金

D.公众养老基金