This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
Vaccination is based on the principle of - 
Select and explain. 
A. Agglunation, B. Phagocytosis, C. Immunologic Memory, D. Clonal Detection
C: Immunologic Memory
Answer: C: Immunologic Memory 
Explanation: Vaccination is aificial active immunity. Active immunity is associated with immunological memory. It is produced actively by host's immune system. Reference : Anathanarayan & paniker's 9th edition, pg no:82,83 <\p>