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': 'By product formed when gypsum binding investment material is heated above 1200 degree centigrade: \nSelect and explain. \nA. SO3, B. CO, C. SO2, D. All of the above.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: If heated above 700 degree centigrade then CO & SO2 are formed.', 'role': 'assistant'}]