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: ENT
[{'content': 'Laryngeal mirror is warmed before use by placing - \nSelect and explain. \nA. Glass surface on flame, B. Back of mirror on flame, C. Whole mirror into flame, D. Mirror in boiling water', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Laryngeal mirror is warmed by: \n\nDipping the mirror in warm water.\nHeating the glass surface against some heat such as bulb or spirit lamp.', 'role': 'assistant'}]