问一道GMATprep上的SC

To meet the rising marketing demand for fish and seafood, suppliers are growing fish twice as fast as their natural growth rate, cutting their feed allotment by nearly half and rasing them on special diets.

A. their natural growth rate, cutting their feed allotment

B. their natural growth rate, their feed allotment cut

C. growing them naturally, cutting their feed allotment

D. they grow naturally, cutting their feed allotment

E. they grow naturally, with their feed allotment cut

答案是D,我选的是C.

搜了一下论坛，发现一个以前讨论的帖子。

http://forum.chasedream.com/dispbbs.asp?BoardID=23&replyID=1195709&id=126890&skin=0

没看懂。

C中growing them naturally和前面未划线的growing fish不正好对应吗？而且这里的them也没有代词指代的问题。

难道naturally只能修饰fish grow.

而不能说supplier grow fish naturally?

请NN指教。

没人看？自己顶一下

D的意思是自然的养鱼

C的意思是鱼自然的生长

楼主觉得哪个逻辑意思更好？