求助一个平行结构题

hxysilvia

A new genetically engineered papaya was produced not by seed companies who have been motivated by profit, which was the case with most genetically modified crops previously approved for commercial use, but university and United States Department of Agriculture researchers who allowed growers to use it free of charge.

A) produced not by seed companies who have been motivated by profit, which was the case with most genetically modified crops previously approved for commercial use, but

B) produced not by profit-motivated seed companies, the case with most genetically modified crops previously approved for commercial use, but

C) produced not by profit-motivated seed companies, as was the case with most genetically modified crops previously approved for commercial use, but by

D) not produced by profit-motivated seed companies, which was the case with most genetically modified crops previously approved for commercial use, but was produced by

E) not produced by seed companies who have been motivated by profit, the case with most genetically modified crops previously approved for commercial use, but by


这个句式对不对？ not by X, but Y
就是把第二个by省略了

还有be vulnerable to A or (to) B
这个to可以省么？

mudiduange

不能省，根据这个结构，答案该是C，不知道是不是
其余内容我没看

第二个to 应该是可以省的