This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anaesthesia
[{'content': 'Longest acting among muscle relaxant is \nSelect and explain. \nA. Doxacurium, B. Rocuronium, C. Vecuronium, D. Atracurium', 'role': 'user'}, {'content': "Answer: A \nExplanation: Among the given options, only doxacurium is long acting(Refer: stoelting's pharmacology and physiology in anaesthetic practice ,5th edition ,pg no.139)", 'role': 'assistant'}]