What is the function of an antibody?

The primary function of an antibody is to produce immunity to an antigen or pathogen. Antibodies are specialized proteins that are produced by B cells in response to foreign invaders, such as bacteria, viruses, or other pathogens. When a pathogen enters the body, antibodies recognize and bind to specific antigens on the surface of these invaders. This binding helps neutralize the pathogen directly or signals other immune cells to destroy it. The presence of antibodies also leads to the formation of immune memory, which equips the body to respond more rapidly and effectively to future infections by the same pathogen.

In contrast, the other options pertain to different biological functions that are not related to antibodies. Blood clotting involves platelets and clotting factors, hormones are produced by endocrine glands and serve various regulatory functions in the body, and digestion is primarily facilitated by digestive enzymes rather than antibodies. Thus, the correct answer highlights the essential role of antibodies in the immune system and their ability to recognize and counteract specific pathogens effectively.