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
K-complex is seen in - 
Select and explain. 
A. REM, B. Stage 1 NREM, C. Stage 2 NREM, D. Stage 3 NREM
C: Stage 2 NREM
Answer: C: Stage 2 NREM 
Explanation: Ans is 'c' i.e., Stage 2 NREM Repeat from all India Dec 2015 of this book