This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharynx, Subject name: ENT
Tonsils reach their maximum size by 
Select and explain. 
A. 1 year, B. 3 years, C. 5 years, D. 12 years
D: 12 years
Answer: D: 12 years 
Explanation: Tonsils are most active from 4 to 10 years of age. Involution begins after pubey resulting in a decrease of B-cell production and a relative increase in the ratio of T to B cells. (Ref: Diseases of Ear, Nose and Throat, PL Dhingra; 7th edition ,pg no. 292)