Which term best describes the immune molecule that targets antigens specifically?

• A. Antigen
• B. Basophil
• C. Antibody
• D. Osteoporosis

Answer: (C)

The molecule that targets antigens specifically is an antibody. Antibodies are proteins produced by B cells that have unique antigen-binding sites shaped to fit a specific part of an antigen, called an epitope. This precise fit allows the antibody to recognize and bind only that antigen, which can neutralize the invader directly or tag it for attack by other parts of the immune system, such as phagocytes or the complement cascade. This targeted binding is the hallmark of humoral immunity and the reason antibodies are described as immune molecules that specifically recognize antigens. Antigen refers to the foreign substance that triggers the response, basophils are inflammatory white blood cells, and osteoporosis is a bone density condition, not a molecule that targets antigens.