This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Muscle relaxants, Subject name: Anaesthesia
[{'content': 'Which of the following is neither metabolized by liver nor by kidney \nSelect and explain. \nA. Atracurium, B. Pancuronium, C. Vecuronium, D. Rocuronium', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Atracurium * two separate processes for metabolism - Ester Hydrolysis (2/3)-catalyzed by nonspecific esterases - Hofmann Elimination (1/3)-spontaneous nonenzymatic chemical breakdown occurs at physiological pH and temperature', 'role': 'assistant'}]