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: Anaesthesia
[{'content': 'Which of the following is the neuromuscular blocking agent with the shortest onset of action ? \nSelect and explain. \nA. Mivacurium, B. Vecuronium, C. Rapacuronium, D. Succinylcholine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Fastest acting (shortest onset of action) muscle relaxant → Succinylcholine\nFastest acting non-depolarizing muscle relaxant → Rocuronium.', 'role': 'assistant'}]