16. T cells (T lymphocytes) are divided into four categories
a. Killer T cells, activating T cells, helper T cells
b. Killer T cells, helper T cells, suppressor T cells, memory T cells
c. Helper T cells, basophilic T cells, suppressor T cells
d. Suppressor T cells, cytotoxic T cells, secondary T cells, primary T cells

17. is a pentamer and the largest of the immunoglobulins.
a. IgG
b. IgA
c. IgD
d. IgM

18. The category of immunoglobulins that can also be found in colostrum and mother’s milk is
a. IgG.
b. IgA.
c. IgD.
d. IgE.