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
[{'content': 'Bronchial secretion secretes - \nSelect and explain. \nA. IgA, B. IgE, C. IgM, D. IgG', 'role': 'user'}, {'content': "Answer: A \nExplanation: 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 the blood Ref: Ananthanarayan & Parker's textbook of microbiology 9th edition pg:97", 'role': 'assistant'}]