What best describes the relationship between antibodies and antigens?

The correct answer highlights the fundamental interaction between antibodies and antigens, which is crucial to understanding how the immune system functions. Antibodies are specialized proteins produced by the immune system, specifically by B cells, in response to the presence of antigens. Antigens are foreign substances, such as bacteria, viruses, or other pathogens, that provoke an immune response.

When antibodies encounter an antigen, they bind to it with high specificity, much like a lock and key mechanism. This binding can neutralize the pathogen directly or mark it for destruction by other immune cells. This specificity is key; each type of antibody is designed to target a particular antigen, which allows for a tailored immune response to various threats that the body may face.

In the context of the other options, they do not accurately describe the interaction between antibodies and antigens. Antigens are not produced by antibodies, nor do antibodies attack other antibodies or are eliminated by antigens. This highlights the unique role that antibodies play in identifying and neutralizing foreign substances in the body.