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 first orthodontic appliance devised by angle was \nSelect and explain. \nA. Edgewise, B. Pin and tube appliance, C. E - arch, D. Ribbon arch', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]