Wind resistance created by opening windows while driving results in a fuel penalty as great or greater than is incurred by using air conditioning.

(A) as great or greater than is incurred by using air conditioning

(B) that is as great or greater than is incurred using air conditioning

(C) as great as or greater than that of using air conditioning

(D) at least as great as air conditioning’s（E）

(E) at least as great as that incurred by using air conditioning

请问c为何不对？多谢各位大牛先

1 at least as great as比as great as or greater简洁

2 that指代wind resistance, 比较的两种情况有平行的关系，即

wind resistance created by opening windows while driving 和 wind resistance incurred by using air condition

E中充分体现了这种平衡，因此更合理。

I don't agree that that refers to wind resistance. I think fuel penalty is what that refers. Therefore, that incurred by using air conditioning precisely converys the meaning that the fuel penalty is caused by using air conditioning. While using that of using air conditioning, we can not see this causal relationship.