In adaptive immunity, which cells differentiate into antibody-secreting plasma cells?

• A. Neutrophils
• B. Eosinophils
• C. B lymphocytes
• D. Basophils

Answer: (C)

Antibody production in adaptive immunity comes from B lymphocytes. When a B cell recognizes its specific antigen and receives help from a T helper cell, it activates and differentiates into plasma cells that secrete antibodies. Plasma cells are specialized for high-volume antibody production, thanks to abundant rough endoplasmic reticulum. These antibodies circulate to bind pathogens, neutralize them, or tag them for destruction by other immune cells. The other cells listed—neutrophils, eosinophils, and basophils—are part of the innate immune system or have roles that don’t involve making antibodies, so they don’t become antibody-secreting cells.