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': 'The root completion of permanent teeth is achieved\nafter _________ years of eruption: \nSelect and explain. \nA. 1 - 1 ½, B. 3-Feb, C. 4-Mar, D. 5-Apr', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]