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: Unknown
In autonomic nervous system, parasympathetic outflow is mainly by 
Select and explain. 
A. Cholinergic, B. Adrenergic, C. Noradrenergic, D. Histaminergic
A: Cholinergic
Answer: A: Cholinergic 
Explanation: None