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
[{'content': 'Slow wave sleep is known as: \nSelect and explain. \nA. REM sleep, B. NREM sleep, C. Both of the above, D. None of the above', 'role': 'user'}, {'content': "Answer: B \nExplanation: 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.", 'role': 'assistant'}]