Which cell type is primarily responsible for antibody production in humoral immunity?

• A. Erythrocytes
• B. Platelets
• C. B lymphocytes
• D. Neutrophils

Answer: (C)

Antibody production in humoral immunity comes from B lymphocytes. When a B cell recognizes its specific antigen, often with help from a helper T cell, it becomes activated and clones itself. Some of these clones become plasma cells, which secrete large amounts of antibodies into the blood and other body fluids. These antibodies can neutralize pathogens, tag them for destruction, help phagocytes recognize invaders (opsonization), and activate the complement system. Memory B cells are also produced, providing quicker responses upon future exposures.

Erythrocytes carry oxygen, platelets help with clotting, and neutrophils are frontline phagocytes of innate immunity; none of these produce antibodies.