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 first evidence of calcification of primary anterior teeth begins approximately between: \nSelect and explain. \nA. 14 to 17 weeks in utero, B. 9 to 12 weeks in utero, C. 6 to 9 weeks in utero, D. 17 to 20 weeks in utero', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]