This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anesthesia, Subject name: Pharmacology
Muscle relaxant of choice in renal and hepatic failure 
Select and explain. 
A. Cis Atracurium, B. Vecuronium, C. Rocuronium, D. Rapacuronium
A: Cis Atracurium
Answer: A: Cis Atracurium 
Explanation: Refer Katzung 9/e p432 Atracurium and cis-Atracurium are muscle relaxants of choice for renal and hepatic failure patients