What is the result of the blockage of the flow of lymph?

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.

A. The portal of entry is the specific site or pathway through which a pathogen enters the body, such as the skin, mucous membranes, or respiratory and digestive tracts.
B. Blood is not the site of entry but rather a medium that can carry pathogens throughout the body once they have entered through a portal of entry.
C. The respiratory tract is a common portal of entry for many pathogens (like viruses or bacteria), but it is just one example of a portal of entry, not the general term for it.
D. Inflammation is an immune response to infection or injury, not a site of entry for