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
Bronchial secretion secretes: 
Select and explain. 
A. IgA, B. IgE, C. IgM, D. IgG
A: IgA
Answer: A: IgA 
Explanation: (IgA) (140 - CP) (89-AN 7th)IgA - Principal immunoglobulin that appears in the sero-mucinous secretions such as milk,, saliva, tears, nasal fluids, sweat and secretions of respiratory, intestinal and genital tracts,