一道英语的物理题, 希望还能有翻译!谢谢the difference between the useful energy transferred by the pulley system and the total energy supplied to the pulley system is called the.a: effective energy b: transferred energyc: transformed energyd: wasted energy

一道英语的物理题, 希望还能有翻译!谢谢
the difference between the useful energy transferred by the pulley system and the total energy supplied to the pulley system is called the.
a: effective energy
b: transferred energy
c: transformed energy
d: wasted energy