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': 'Frankel appliance is a: \nSelect and explain. \nA. Myofunctional appliance, B. Removable appliance, C. Fixed appliance, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Frankel appliance is a removable myofunctional appliance.', 'role': 'assistant'}]