The Capacity of Immune Systems to Protect Against Pathogens

The capacity of immune systems to protect against pathogens

A) is a consequence of a small number of inherited genetic elements which are randomly rearranged during differentiation of specific immune cells.
B) is a consequence of a very large number of inherited genetic elements which produce individual lymphocytes carrying a distinct antigen receptor.
C) depends on mounting an inflammatory response at the site of infection.
D) is principally a function of the physical and chemical barriers and the action of phagocytic cells in conjunction with the complement system which prevent pathogens from becoming established.
E) depends on the effective screening of lymphocytes in the thymus, spleen and bone marrow to prevent the release of cells with receptors which can bind with molecules on the surfaces of self cells as if they were antigens.