In the Afternoon, Bill Has Great Difficulty Staying Awake During

Multiple Choice

In the afternoon, Bill has great difficulty staying awake during his math class. Even if he is well rested and interested in the material that is being presented, he often suddenly falls asleep. In fact, it is not unusual for this kind of behaviour to happen to him during other times of the day as well. Bill most likely suffers from

A) insomnia
B) REM-sleep behaviour disorder
C) a melatonin deficiency
D) narcolepsy