Why Does Passive Immunity Not Give Lifetime Protection, While Active

Multiple Choice

Why does passive immunity not give lifetime protection, while active immunity may?

A) In active immunity, the body's own lymphocytes respond, producing a memory cell population that can respond to a subsequent exposure to the same antigen. Passive immunity only lasts as long as the injected antibodies remain in the body.
B) In passive immunity, the body's own lymphocytes respond, producing a memory cell population that can respond to a subsequent exposure to the same antigen. Active immunity only lasts as long as the injected antibodies remain in the body.
C) In active immunity, the body's own lymphocytes respond, producing an effector cell population that continually produces antibodies for the duration of the person's lifetime. Passive immunity only lasts as long as the injected antibodies remain in the body.
D) In active immunity, the body's own lymphocytes respond, producing an effector cell population that continually produces antibodies for the duration of the person's lifetime. Passive immunity results in the production of antibodies only when an antigen is present.
E) This question is misleading. Both passive immunity and active immunity provide lifetime protection.