Match the antibody class with its description.

a. this class of antibody is the only one that can cross the placenta.

b. this class of antibody is the first to appear after activation of b cells.

c. this class of antibody is involved in the defense against parasitic infections and involved in allergic responses.

d. this class of antibody is found in very large amounts in mucus secretions.

e. this class of antibody is not secreted by b cells but is expressed on the surface of naã¯ve b cells.

1. IgA refers to the class of antibody, which is witnessed in very large concentrations in mucus secretions.  

2. IgD refers to the class of antibody, which is not discharged by B cells, however, is expressed in the naive B cells' surface.  

3. IgE refers to the class of antibody, which takes part in the defense against the infections caused by parasites, and also takes part in allergic reactions.  

4. IgG refers to the class of antibody that can pass through the placenta.  

5. IgM refers to the class of antibody that is the first to appear post-stimulation of B cells.