Which of the Following Antibodies is a Dimer

Question

Which of the following antibodies is a dimer?
A)IgA
B)IgD
C)IgM
D)IgE

Accepted Answer

IgA is the only antibody that exists as both a monomer and a dimer. The dimeric form is found in secretions such as milk, tears, and saliva, and provides protection against pathogens in these fluids.