This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition, Subject name: Pediatrics
The protective effects of breast milk are known to be associated with ___________ 
Select and explain. 
A. IgM antibodies, B. Lysozyme, C. Mast cells, D. IgA antibodies
D: IgA antibodies
Answer: D: IgA antibodies 
Explanation: Human milk contains high concentrations of secretory IgA that prevent microorganisms from adhering to the intestinal mucosa. These protect against many infections. Ref: Page 215; Nelson textbook of pediatrics; 18th edition