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': 'A 12-year-old boy presented to the orthodontic clinic with irregularity of his front teeth. Intraoral examination reveals class I molar relationship and crowding of maxillary and mandibular teeth. Orthodontic diagnosis is: \nSelect and explain. \nA. Class I type 1, B. Class I type 2, C. Class I type 3, D. Class I type 4', 'role': 'user'}, {'content': "Answer: A \nExplanation: Dewey divided Angle’s class I into 5 types and Angle's class III into 3 types.", 'role': 'assistant'}]