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': 'Eruption of Mandibular 2nd molar occur at \nSelect and explain. \nA. 11-12 year, B. 12-13 year, C. 14-15 year, D. 13-15 year', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]