In 1960's studies of rats, scientists found that crowding increases the number of attacks among the animals significantly. But in recent experiments in which rhesus monkeys were placed in crowded conditions, although there was an increase in instances of "coping" behavior-such as submissive gestures and avoidance of dominant individuals-attacks did not become any more frequent. Therefore it is not likely that, for any species of monkey, crowding increases aggression as significantly as was seen in rats.
Which of the following, if true, most strengthens the argument?
原文从“r猴”不怎么表现攻击,推出结论:“any” species of monkey也不会表现攻击,若如C所说,那么就削弱了这个推理
D正确,因为although there was an increase in instances of “coping” behavior—such as submissive gestures and avoidance of dominant individuals—attacks did not become any more frequent,就是as frequent as或less frequent,但总之还是frequent,所以对应Some individual monkeys in the experiment were involved in significantly more attacks than the other monkeys were.