Why are people with Type O blood considered universal donors? aTheir erythrocytes have both the A and the B antigens, so their body doesn't make any antibodies bTheir erythrocytes have neither the A nor the B antigen, so there are no antigens to induce an immune response in the recipient cTheir erythrocytes have neither the A nor the B antigen, so their body doesn't make any antibodies dTheir erythrocytes may have the A or the B antigen, so they mutate to conform to the recipient's blood type