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
All of the following are NREM sleep disorders except 
Select and explain. 
A. Somnambulism, B. Pavor nocturnus, C. Nightmares, D. Somniloquy
C: Nightmares
Answer: C: Nightmares 
Explanation: None