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': 'NORWEGIAN APPLIANCE is? \nSelect and explain. \nA. Bionator, B. Activator, C. Frankel, D. Twin block', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Other names of activator\n\nNorwegian appliance\nFunctional jaw orthopedics.', 'role': 'assistant'}]