Which of the following is most related to the placental transfer of antibodies from the mother to the fetus?

A. Pharyngeal tonsils (also called adenoids) are located in the nasopharynx, not at the back of the tongue.
B. Palatine tonsils are located on either side of the back of the throat, not at the back of the tongue.
C. Lingual tonsils are small mounds of lymphoid tissue located at the base of the tongue, and they help protect the body from pathogens entering through the oral cavity.
D. Adenoids are another term for the pharyngeal tonsils, which are located in the nasopharynx, not at the back of the tongue.

A. Autoimmunity is a malfunction of the immune system where the body attacks its own tissues — it is not a type of protective immunity acquired through infection or exposure.
B. Species immunity refers to natural resistance to certain diseases that affect other species (e.g., humans not being susceptible to some animal viruses), not immunity acquired through infection.
C. Passive immunity involves receiving antibodies from another source (like from mother to baby or via antibody-containing injections) and does not require the immune system to produce its own response.
D. Active immunity is the correct answer. It develops when the body is exposed to a pathogen or its toxins and responds by producing its own antibodies and memory cells, providing long-term protection.