The Efficiency and Specificity of Adaptive Immune Defenses and Immunological

Multiple Choice

The efficiency and specificity of adaptive immune defenses and immunological memory improve each time a particular pathogen is encountered because _____.

A) of protective immunity
B) effector memory T cells outnumber central memory T cells
C) the half-life of antibodies made in secondary and tertiary immune responses exceeds that of antibodies made in primary immune responses.
D) of affinity maturation.