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
[{'content': 'Pirenzepine acts on which receptor? \nSelect and explain. \nA. Muscarinic, B. Nicotinic, C. Alfa, D. Beta', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ref; KD Tripathi pharmacology (page no;117) Pirenzepine act through muscarinic receptor it selectively blocks M1 receptor and inhibits gastric secretion without producing other atropinic side effects due to M2& M3 blockade.', 'role': 'assistant'}]