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
Gingivitis is at its peak in children at age: 
Select and explain. 
A. 3 - 4 years, B. 6 - 7 years, C. 11 - 13 years, D. 15 -18 years
C: 11 - 13 years
Answer: C: 11 - 13 years 
Explanation: None