Question for OG233

sleep cycle have reduced sickness, sleeping on the job, fatigue among shift workers, and have raised production efficiency in various industries.

(A) fatigue among shift workers, and have raised

(B) fatigue among shift workers, and raised

(C) and fatigue among shift workers while raising

(D) lowered fatigue among shift workers, and raised（C）

(E) and fatigue among shift workers was lowered while raising

The best answer, C, grammatically states that the equations... have reduced x, y, and z. and have raised efficiency. Choices A and B fail to use and to signal that fatigue among shift workers completes the series begun by have reduced, and so produce awkward and unclear sentences. Both D and E fail to use and to introduce the last item in the list, which is sleeping in these constructions. In E, while raising has no logical referent, producing only the absurd statement that fatigue has raised efficiency.

here is the problem:

Does "raising" in option C equal to "have raised" in this case?

Thanks a lot!

Then~~~I guess it is.

Thanks!

不明白

raising 怎么和have reduced平行的？

另外，while后面是一个短语而不是句子，这样可以是么？

sleep cycle have reduced sickness, sleeping on the job, and （sleep cycle have reduced）fatigue among shift workers while raising production efficiency in various industries.

while的一种用法：while +动词ing ，现在分词短语和主句的动作形成强烈对比关系。可译为：同时。。。却，强调动作同时发生。－lzm

所以raise和have reduced有相同主语就不难理解他们的平行了

while 在这里做介词可以接phrase.

ETS好像比较喜欢这种 present participle 和 past participle的用法

还是不明白