Immunization with the childhood DPT (diphtheria, pertussis, and tetanus) vaccine protects against subsequent exposure to tetanus by

A) stopping isotype switching of B cells from IgM to IgA.
B) preloading antigen-presenting cells.
C) stimulating quick inflammation upon future exposure.
D) producing life-spanning antitetanus IgE antibodies.
E) generating tetanus-specific memory B cells.