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': 'Advantage of LMA are all except \nSelect and explain. \nA. Easy to inse, B. Aspiration is prevented, C. Can be used in cervical trauma, D. Does not require muscle relaxant', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Aspiration is prevented', 'role': 'assistant'}]