[求助]大全855-11-24

24.   The labor agreement permits staff reductions through attrition with increased pension benefits and a special early-retirement program for speeding it up.

(A) attrition with increased pension benefits and a special early-retirement program for speeding it up

(B) attrition and provides increased pension benefits and a special early-retirement program to speed the attrition process

(C) attrition, which will be speeded up by providing increased pension benefits and a special early-retirement program

(D) attrition, which, by their providing increased pension benefits and a special early-retirement program, will speed the process（B）

(E) attrition, which provides increased pension benefits and a special early-retirement program for speeding the attrition process

请问c为什么不对呢？觉得b有改变句子重心的嫌疑