GRE Reading Comprehension: JiJing 352-GRE阅读机经352篇 - QH_0DMUMO088JNR8J

Based on the discussion of Kaminski et al., which of the following situations would indicate to a chimpanzee that it cannot be seen by a human? A. The human's body is facing the chimpanzee, but the human's face is turned away. B. The human's body is turned away, but the human's face is turned over the shoulder toward the chimpanzee. C. The human's body and head are both facing away from the chimpanzee.