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
Till what age tetracycline should not be given to prevent discoloration 
Select and explain. 
A. 3 year, B. 8 year, C. 12 year, D. 18 year
B: 8 year
Answer: B: 8 year 
Explanation: None