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': 'To cure a heat cure resin, a proper heating cycle is necessary: \nSelect and explain. \nA. To prevent the porosity, B. To prevent warpage, C. To prevent volume expansion, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]