Which of the following immunoglobulins does constitute the largest percentage in human milk?

IgG: Smallest antibody. Only antibody that move through placenta and provide passive immunity in foetus. It occurs in form of monomer.
IgA: Only antibody that move through colostrum and provide passive immunity in infants. It occurs in form of dimer.
IgM: Largest antibody. It occurs in form of pentamer. Hence, a single antibody can negate the effect of 10 antigens. 
IgD: Very rare form of antibody. It occurs in form of monomer.
IgE: It is responsible for inducing allergic reactions and hypersensitivity