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
[{'content': 'Centrally acting muscle relaxant: \nSelect and explain. \nA. Chlorzoxazone, B. Scoline, C. Atracurium, D. Vecuronium', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ref. Oxford textbook of anesthesia. Page. 309\n\xa0\nChlorzoxazone\n\nIt’s a centrally acting muscle relaxant\nChlorzoxazone may act by inhibiting calcium and potassium influx which would lead to neuronal inhibition and muscle relaxation.\nChlorzoxazone inhibits degranulation of mast cells, subsequently preventing the release of histamine and slow-reacting substance of anaphylaxis (SRS-A), mediators of type I allergic reactions.\nChlorzoxazone also may reduce the release of inflammatory leukotrienes.', 'role': 'assistant'}]