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
Active immunity is not acquired by: 
Select and explain. 
A. Infection, B. Vaccination, C. Immunoglobulin transfer, D. Sub - clinical infection
C: Immunoglobulin transfer
Answer: C: Immunoglobulin transfer 
Explanation: Ans. is 'c' i.e., Immunoglobulin transfer (Ref: Ananthanarayan, 9th/e, p. 82 - 83 and 8th/e, p. 86, 87)* Immunoglobulin transfer gives passive immunity.* Rest of the other options are examples of active immunity.