Answer: You conclude that the sleeping person is in REM.
Step-by-step explanation:
REM (rapid eye movement) is the last stage of the sleeping cycle. It happens after about 90 min approximately from the beginning of the first sleeping stage.
Characteristics of REM: muscle tone has no existence, that’s the reason why we cannot scream in a dream; the predominant brain waves are theta; blood pressure and heat frequency increase; eye movement also increases while in the other hand muscles are paralyzed.
In this stage is when we dream and if we were woken up we would remember it.