TOEFL Reading: ETS-TOEFL阅读机经 - ADK5WXGQT5XLH4T6L$

Paragraph 3 suggests that comparative behaviorists' conclusions concerning animal behavior were based A. on the observation that rewards do not affect inherited animal behavior B. on the application of stress to modify animal behavior C. most often on the results of laboratory experiments D. more on stimulus/response reactions than on simple rewards