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': '1st evidence of calcification of Upper 3rd molar is seen in \nSelect and explain. \nA. at birth, B. 7-8 year, C. 10 year after birth, D. 12 years after birth', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]