This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sleep Physiology, Subject name: Physiology
[{'content': 'K-complex is seen in - \nSelect and explain. \nA. REM, B. Stage 1 NREM, C. Stage 2 NREM, D. Stage 3 NREM', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans is 'c' i.e., Stage 2 NREM Repeat from all India Dec 2015 of this book", 'role': 'assistant'}]