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
First immunoglobulin to appear following infection- 
Select and explain. 
A. IgG, B. IgM, C. IgA, D. IgE
B: IgM
Answer: B: IgM 
Explanation: Ans. is 'b' i.e., IgM