Final answer:
Option (A), Deprivation of REM sleep can cause anxiety, irritability, increased hunger, and concentration difficulties. It is essential for learning and memory, and emotional regulation.
Step-by-step explanation:
Experimenters have found that when a person is deprived of REM sleep, they may become anxious, testy, and hungry, and have difficulty concentrating. REM sleep, or Rapid Eye Movement sleep, is characterized by rapid movements of the eyes, paralysis of voluntary muscles, and dreaming. This stage is crucial for processes related to learning and memory, and it plays a role in the regulation of emotions.
The lack of REM sleep can result in significant psychological and physiological impacts on an individual, including increased irritability, difficulty concentrating, and an increase in appetite. Conversely, during periods of sleep deprivation, the body will try to compensate by increasing the duration of REM sleep when next able to sleep, a phenomenon known as REM rebound.