Why does a person with type AB blood carry neither anti-A nor anti-B antibodies?

1. Type AB erythrocytes carry both the A antigen and the B antigen. 2. Anything present on a person's own cells is read as self. 3. Since both antigens are self, there is nothing in the ABO group left to raise an antibody against. 4. Type AB plasma therefore carries neither anti-A nor anti-B. 5. Saying both antigens are absent describes type O, which is the exact inversion and produces both antibodies rather than neither. 6. ABO antibodies are preformed without exposure, so the option requiring a prior transfusion describes Rh sensitisation instead. 7. Plasma cells in a type AB person make antibodies normally against everything else, so the defect suggested in the last option does not exist. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 18 "The Cardiovascular System: Blood", section 18.6 Blood Typing_