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: Pharmacology
[{'content': 'Vecuronium acts on \nSelect and explain. \nA. Cerebral cortex, B. Myoneural junction, C. Muscle fibres, D. Spinal cord', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Vecuronium is a non-depolarizing neuromuscular blocking agent.\nIt acts on the nicotinic receptor at neuromuscular junctions and blocks the depolarization by inhibiting Na+ channels.', 'role': 'assistant'}]