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
Immunoglobulin which is produced first by the fetus in response to infection:(1987) 
Select and explain. 
A. IgG, B. IgA, C. IgM, D. IgD
C: IgM
Answer: C: IgM 
Explanation: Ans: c (IgM)Ref: Ananthanarayan Micro, 7thed, p. 89 & 6th ed, p. 83, 84