[求助] gmat BY语法

39.        In terms of physics, the characteristic feature of the roller coaster is that the cars’ potential energy, gained through their being lifted by a chain drive through the Earth’s gravity to the top of the first drop, has been converted to kinetic energy by the time the ride ends.

(A) cars’ potential energy, gained through their being lifted by a chain drive

(B) cars’ potential energy, a gain achieved as they are lifted by a chain drive

(C) potential energy from the cars’ being lifted by a chain drive

(D) potential energy of the cars, gained as a chain drive lifts them（D）

(E) potential energy gained by the cars, being achieved while a chain drive lifts them

我觉得A,C.D中使用being不太合适.请问这么理解对吗?

BY说是A.C项 potential energy   被动动作产生的,逻辑意思别扭.可我觉得挺顺的呀?