—Excuse me, sir. Would you do me a favor?

—Of course. What is it?

—I ________ if you could tell me how to fill out this form.

A．had wondered

B．was wondering

C．would wonder

D．did wonder

某矿山5月开采铜矿石20000吨，没有原矿销售，入选精矿3000吨，选矿比30%，铜矿单位税额1.2元/吨，其当月应纳资源税为( )。

A．24000元

B．3600元

C．12000元

D．8400元