TOEFL Reading: ETS-TOEFL阅读机经 - 1W3D5F97CNY0W0D5L$

According to paragraph 4, farmers found horses to be better than oxen for pulling plows for all of the following reasons EXCEPT: A. Horses are smarter than oxen. B. Horses can pull plows faster. C. Horses are able to plow for longer periods of time. D. Horses do not need verbal signals to turn and stop.