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': 'Ceramics fired to metals are processed by \nSelect and explain. \nA. Heat pressing, B. Machining, C. Sintering, D. Slip casting', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]