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
Hand over mouth exercise (HOME) is an effective behavioral modification technique in the age group of: 
Select and explain. 
A. 3 to 6 years, B. Under 3 years, C. 6 to 9 years, D. Above 9 years
A: 3 to 6 years
Answer: A: 3 to 6 years 
Explanation: None