这是一个通篇的中心归纳的考察题。文章一开始就指出“Before a big exam，a sound night’s sleep will do you better than poring over textbooks．”意思是在晚上好好的睡觉对记忆是有好处的。最后作者有归纳了研究的结果，“．．．concluded that the nerve connections involved in memory are reinforced through reactivation during REM sleep，．．．”也说明结构性知识在REM睡眠中是可以巩固的。故应选D。