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 present in local secretion is? 
Select and explain. 
A. IgG, B. IgA, C. IgM, D. IgD
B: IgA
Answer: B: IgA 
Explanation: In its secretory form, IgA is the main immunoglobulin found in mucous secretions, including tears, saliva, sweat, colostrum and secretions from the genitourinary tract, gastrointestinal tract, prostate and respiratory epithelium. It is also found in small amounts in blood. Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pg:98