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
Crown completion of Maxillary central incisors occur 
Select and explain. 
A. At birth, B. 4-5 year after birth, C. 11-12 year after birth after birth, D. 6 months after birth
B: 4-5 year after birth
Answer: B: 4-5 year after birth 
Explanation: None