Answer:
is not making antibodies against antigens outside the ABO or Rh systems.
Explanation:
Red blood cells have many protein and carbohydrates antigens on its surface , there are about 600 antigens , which are further divided into 20 blood groups .
The presence or absence of antigens determines the type of blood which can be given in the case of blood transfusion .
Anti - A and Anti - B are the only naturally occuring RBC antibodies in the normal human plasma or serum . Others are classified as alloantibodies and autoantibodies .