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': 'Base metal alloys are useful for \nSelect and explain. \nA. Cast partial dentures, B. Crowns, C. Orthodontic wires, D. all of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]