If, in midsentence, your friend suddenly slumps over on the couch and appears to have entered the REM stage of sleep, which of the following is the BEST explanation for your friend's behavior?
a. Your friend did not get enough sleep last night and should go to bed.
b. Your friend suffers from epilepsy and just had a seizure.
c. Your friend suffers from narcolepsy and should seek medical attention.
d. You are boring and should take a class in social speaking skills.

The correct answer is letter C

Narcolepsy is a sleep disorder characterized by excessive sleepiness during the day, even when the person slept well at night. Sleep attacks can occur at any time and in unusual situations: standing on a bus, during a medical consultation, driving the car, or operating machines, for example.  

Normal sleep begins with turning off muscle control. In this phase, it is a sleep of slow waves. About an hour and a half later, the person enters the REM sleep phase, in which the brain activity is intense and the eyes move. People with narcolepsy skip the slow wave sleep stage and suddenly go straight to REM sleep.

because the early people found out about it.