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
Traumatic injury to primary tooth Leads to intrusion,
after how much time the teeth usually re-erupts? 
Select and explain. 
A. 30 Days, B. 3 Months, C. 6 Months, D. 12 Months
C: 6 Months
Answer: C: 6 Months 
Explanation: None