Final answer:
Passive immunity typically lasts from days to months as it involves the transfer of external antibodies that provide immediate but temporary protection against specific pathogens. The correct option is B.
Step-by-step explanation:
Passive immunity generally lasts from days to months. It is acquired when antibodies are transferred to a person who has not been previously exposed to the pathogen.
These antibodies, whether received naturally through maternal-fetal transfer, through breast milk, or artificially by the injection of antibodies, are temporary and do not impart long-term immunological memory.
The presence of transferred antibodies provides immediate protection against the specific pathogen but will eventually degrade and be removed from the bloodstream, hence the protection is not permanent.