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': 'At birth the following teeth are calcifying: \nSelect and explain. \nA. Primary incisors & first molar, B. Primary canines & second molars, C. Permanent canines, D. Permanent 3rd molar', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]