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': 'Ideal Time to start an orthodontic treatment is? \nSelect and explain. \nA. Primary Dentition, B. Early Mixed Dentition, C. Late Mixed Dentition, D. When the malocclusion first seen', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]