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: Microbiology
A full course of immunization against, Tetanus with 3 doses to Tetanus toxoid, confers immunity for how many years? 
Select and explain. 
A. 5, B. 10, C. 15, D. 20
B: 10
Answer: B: 10 
Explanation: None