This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sleep Disorders, Subject name: Psychiatry
What is D - Sleep ? 
Select and explain. 
A. NREM sleep, B. REM sleep, C. Deep sleep, D. Drug induced sleep
B: REM sleep
Answer: B: REM sleep 
Explanation: D - Sleep is the other name for Desynchronized sleep or the REM sleep. The alternative names for REM sleep are: Desynchronized sleep (D - Sleep) Dream sleep Active sleep Paradoxical sleep