TOEFL Reading: ETS-TOEFL阅读机经 - AWCTHV_494POG3RJL$

According to paragraph 4, why did comparative behaviorists believe that their view of instinct in animal behavior was correct? A. They had observed that animals can respond to the same stimulus in different ways. B. They had demonstrated that animals could use learned behaviors in new conditions. C. They had acquired sufficient evidence that instincts vary from one animal to another. D. They had shown that the behavior of many different animals had been changed by learning.