句子改错：GWD-3-Q30
Today’s technology allows manufacturers to make small cars more fuel-efficient now than at any time in their production history.
A. small cars more fuel-efficient now than at any time in their
B. small cars that are more fuel-efficient than they were at any time in their
C. small cars that are more fuel-efficient than those at any other time in
D. more fuel-efficient small cars than those at any other time in their
E.more fuel-efficient small cars now than at any time in
why not D? The correct answer is C. But according with OG, is D better? | 
