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
A six-year molar begins to calcify at: 
Select and explain. 
A. Six months IU, B. At birth, C. 1 year after birth, D. 3 years age
B: At birth
Answer: B: At birth 
Explanation: None