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 SCAN index is generally used as a \nSelect and explain. \nA. Malocclusion index, B. Treatment need index, C. Treatment change index, D. Treatment of priority index', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]