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: Psychiatry
Not true about nocturnal penile tumerscence is 
Select and explain. 
A. Totals about 100 min / night, B. Normal phenomenon, C. Occurs in NREM sleep, D. Can be used to distinguish between psychological or organic impotence.
B: Normal phenomenon
Answer: B: Normal phenomenon 
Explanation: B i.e. Sleep walking