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
Biological marker for antisocial behavior in boys is : 
Select and explain. 
A. Low serum testosterone, B. Shortened REM latency time, C. Low resting pulse rate, D. Increased urinary dopamine levels
C: Low resting pulse rate
Answer: C: Low resting pulse rate 
Explanation: Low resting pulse rate is the constant predictor of conduct and antisocial behavior.