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': 'In mixed dentition analysis, which tooth is used for classification? \nSelect and explain. \nA. Primary 1st molar, B. Primary 2nd molar, C. Permanent 1st molar, D. Any of 2 or 3', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The first permanent teeth to erupt into oral cavity is permanent first molar.\xa0\nFrom that\xa0phase of dentition, it is called as mixed dentition.\nOnce the\xa0first permanent molar erupts into occlusion, it is used for the classification of malocclusion.', 'role': 'assistant'}]