The protective effects of breast milk are known to be associated with:: (A) IgM antibodies, (B) Lysozyme, (C) Mast cells, (D) IgA antibodies
Answer is D. d. IgA antibodies(Ref: Nelson's 20/e p 286-290, Ghai 8/e p 150-161)Although antibodies & lysozyme, both are important for protective effects of breast milk, antibodies (IgA) play a major role.