A) the immune system destroys foreign invader molecules.
B) antibodies are specific in the molecules they bind to.
C) drugs destroy specific types of antibodies.
D) antibodies change by mutation.
Immunodetection is a method of detecting possible antigens (or foreign bodies) either by the organisms’ immune system itself or the use of immunodectection kit which utilizes antibodies as detectors. This specific antibody allows the detection, localization and quantification of antigens in the process of antibody binding.
Examples of immunodetection methods are western blotting, ELISA (Enzyme-linked immunosorbent assay), immuno-staining, RIA (radio immuno assay), immunoprecipitation, etc...
Looking at the questions, we can see that immunodetection works because B. antibodies are specific in the molecules they bind to. This is the best answer among the other choices given.