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': '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: None', 'role': 'assistant'}]