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
At birth the following teeth are calcifying: 
Select and explain. 
A. Primary incisors & first molar, B. Primary canines & second molars, C. Permanent canines, D. Permanent 3rd molar
A: Primary incisors & first molar
Answer: A: Primary incisors & first molar 
Explanation: None