This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anaesthesia, Subject name: Pharmacology
[{'content': 'Muscle relaxant of choice in renal and hepatic failure is: \nSelect and explain. \nA. Cis-atracurium, B. Vecuronium, C. Rocuronium, D. Rapacuronium', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (A) Cis-atracurium(Ref: Katzung 9th/e p432; KDT 8th/e p380)Atracurium and cis-atracurium are muscle relaxants of choice for renal and hepatic failure patients.', 'role': 'assistant'}]