Why doesn't passive immunity last very long?

A. Antibodies from outside our bodies are destroyed quickly by our own immune system.

B. Most antibodies to a pathogen are destroyed by that pathogen.

C. Another person's antibodies are not as strong as our own antibodies.

D. Memory cells against a pathogen are not produced when antibodies are transferred to a person's body.

E. Passive immunity is not possible in humans; humans are never exposed to antibodies that have been transferred from another person.