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
Binary (secondary) exposure to an antigen results in sudden increase in - 
Select and explain. 
A. IgA, B. IgD, C. IgG, D. IgM
C: IgG
Answer: C: IgG 
Explanation: Secondary response: the response to subsequent stimuli with the same antigen. Usually 100-1000 times more than primary response. IgG is responsible for the secondary response. Reference: Anathanarayan & paniker's 9th edition, pg no:146 <\p>