This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autonomic nervous system, Subject name: Pharmacology
The following are the sites of ion channel cholinergic receptors except 
Select and explain. 
A. Adrenal medulla, B. Bronchial muscle, C. Skeletal muscle, D. Ganglia
B: Bronchial muscle
Answer: B: Bronchial muscle 
Explanation: NM, NN are ion channel receptors. bronchial muscle contains M3 receptors which are GPCR Ref: KDT 7th ed pg 101