IgA Is Typically Found as a Dimer in High Levels

IgA is typically found as a dimer in high levels of secretions such as milk, tears, and saliva.What is the primary function of IgA in secretions?

A) To alert plasma cells of an invading pathogen
B) To neutralize toxins and pathogens
C) To secrete nonspecific enzymes such as lysozyme
D) To stimulate the growth of normal microbiota (normal flora) species
E) To trigger apoptosis in infected mucosal cells