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': 'Crown formation of all permenent teeth except third molars is completed between \nSelect and explain. \nA. Birth to 8 years, B. Birth to 12 years, C. Birth to 6 years, D. 6 years to 12 years', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]