Correct Option: C

ELISA is an abbreviation for “enzyme-linked immuno-sorbent assay.” An ELISA test uses components of the immune system and chemicals to detect immune responses in the body (for example, to infectious microbes).It is used to detect the retrovirus antibodies. The ELISA test involves an enzyme (a protein that catalyzes a biochemical reaction). It also involves an antibody or antigen (immunologic molecules).