This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
A full course of immunization against, Tetanus with 3 doses of Tetanus toxoid, confers immunity for how many years - 
Select and explain. 
A. 5, B. 10, C. 15, D. 20
A: 5
Answer: A: 5 
Explanation: <p> 5 years TT given as a primary course of immunisation of two doses at interval of 1-2 month.then a booster after 1 year. The opinion was expressed that no more than one additional. Booster dose given 5 year after the third dose is required in adult in developing countries. Reference:Park&;s textbook of preventive and social medicine,K.Park,23rd edition,page no:312. <\p>