This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sleep disorders and eating disorders, Subject name: Psychiatry
Ponto Geniculo Occipital spike is characteristic of ------- sleep 
Select and explain. 
A. Stage 1 NREM, B. Stage 2 NREM, C. Stage 4 NREM, D. REM
D: REM
Answer: D: REM 
Explanation: PGO waves are prominent phasic bioelectrical , closely related to rapid eye , that occur in or during Ref: Principles and practice of sleep medicine, 6e, 2017.