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: Dental
[{'content': "The low thermal conductivity of impression compound is overcome by: \nSelect and explain. \nA. Impression is placed in mouth till it gets cold and sudden removal of impression, B. By melting in boiling water at 50°c for one hour, C. By heating with ethanol frame and directly placing in patient's mouth., D. Heating in hot water and immediately quenching in water for 20 minutes", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]