Answer:
Agglutination test of antigen-antibody
Step-by-step explanation:
Immunologic tests or methods are used to identify the presence of antibodies to a pathogen in the specimens of the patient.
Agglutination tests is an immunologic test used to identify the microbes in the specimens of the patient. In the agglutination test, a specimen such as red blood cells are taken which are then coated with antigen, if antibody forms clumps with antigen, it shows visible clumping of bacterial cells against the particular antibody.
Hence, the correct option is Agglutination test of antigen-antobody.