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
Muscle relaxant of choice in renal and hepatic failure is : 
Select and explain. 
A. Cis–atracurium, B. Vecuronium, C. Rocuronium, D. Rapacuronium
A: Cis–atracurium
Answer: A: Cis–atracurium 
Explanation: None