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: Physiology
[{'content': 'Which muscarinic receptor causes dilatation of vessels? \nSelect and explain. \nA. M1, B. M2, C. M3, D. M4', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., M3(Ref: Rapid Review of Physiology p.j32)M3 receptors are found in vessels (endothelium).Activation of these receptors causes vasodilation by release of EDRF(NO).Unique muscarinic receptors in that their activation does not cause release of acetylcholine, rather causes release of EDRF(NO).", 'role': 'assistant'}]