In Spite of Their Low Affinity for Binding to Their

In spite of their low affinity for binding to their antigen, IgM antibodies can be quite effective at promoting the elimination of extracellular bacterial infections. This is due to:

A) The ability of IgM antibodies to traffic across epithelial surfaces
B) Multivalent binding of IgM pentamers to repetitive epitopes on bacterial surfaces
C) The high concentration of IgM antibodies in the serum and in all tissues
D) The early production of IgM antibodies during an immune response
E) The high rate of somatic hypermutation in the genes encoding IgM antibodies