_____ I believe, and you will find Tom is very outgoing. [ ]

A. Having a talk with the student

B. One talk with the student

C. Given a talk with the student

D. If you have a talk with the student

下列可用资源的机会成本计算影子价格的资源是( )。

A．水

B．森林

C．矿产

D．空气