one more, need help!!!

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

as great as or greater than. 固定用法.