This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Slow wave sleep is known as: 
Select and explain. 
A. REM sleep, B. NREM sleep, C. Both of the above, D. None of the above
B: NREM sleep
Answer: B: NREM sleep 
Explanation: This is a straight forward memory question. There are two kinds of sleep: rapid eye movement (REM) sleep and non-REM (NREM), or slow-wave sleep. Ref: Ganong's Review of Medical Physiology 23rd edition, Chapter 15.