<prompt> Direct Coombs test detects:Antibodies attached to RBC SurfaceAntibodies in the serumAntigens attached to RBC SurfaceAntigens in the serum  <response>: Answer is A Antibodies attached to RBC Surface Direct Coombs test detects IgG Antibodies or complements attached to the surface of RBCs. Indirect Coombs test detects IgG antibodies in the serum e.g. Anti-D Antibodies. 