James Has Been Sleeping for About 90 Minutes When His

Multiple Choice

James has been sleeping for about 90 minutes when his brain shows rapid, irregular waves. His blood pressure rises, his heart rate increases, and his skeletal muscles go limp. Which of the following is the most likely conclusion?

A) James is chronically sleep-deprived and his sleep, like his daytime activities, is abnormal.
B) James is experiencing physiological changes that are normal for the third stage of sleep.
C) James is experiencing unusual sleep because during the day he engaged in strenuous physical activities.
D) James is experiencing physiological changes that are normal during REM sleep.