Secretory IgA is best described as . A. an opsonizing antibody that facilitates uptake by M cells through Fc receptors
B. a monomeric IgA that neutralizes antigen effectively at mucosal surfaces
C. an inflammatory immunoglobulin that stimulates the chemotaxis of neutrophils into mucosal surfaces
D. a complement-activating immunoglobulin that causes destruction of invasive microflora through the membrane-attack complex
E. a non-inflammatory immunoglobulin that restricts the passage of antigens across mucosal surfaces