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': 'Rapid maxillary expansion is not indicated after: \nSelect and explain. \nA. 6 years, B. 9 years, C. 12 years, D. 15 years', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]