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
Secretory component is present in: 
Select and explain. 
A. IgA, B. IgG, C. IgM, D. All of these
A: IgA
Answer: A: IgA 
Explanation: IgA are the secretory antibodies seen in seromucous secretions of gastrointestinal tract, nasopharyngeal tract, urogenital tract, tears, saliva, sweat, etc.,
Reference: Vasudevan 7th  ed, pg 689