TOEFL Reading: ETS-TOEFL阅读机经 - 307WLX5762VGM513L$

Paragraph 5 suggests that before the more specific prediction based on the kin-selection hypothesis is tested, researchers involved in the testing should know A. the minimum number of members needed as guards B. which group members were related to each other C. which group members were more skilled at standing guard D. how well group members were protected by the sentinels