“必须求出此电阻上的电压和电流。”一句的英文表达，哪一项正确？

A.It is necessary to find out the voltage and current of this resistor.

B.It is necessary to find out the voltage and current on this resistor.

C.It is necessary to find out the voltage and current for this resistor.

D.It is necessary to find out the voltage across and current through this resistor.

正确答案：It is necessary to find out the voltage across and current through this resistor.