What about AB? Well, AB is the same exact case on AB red blood cells. We have both antigen A and antigen B. And since this produces antigen B's, antibody B, the antibody B will bind onto a B red blood cells, destroying those red blood cells, forming this Agglutination process. And so this and this is not allowed. But if we take an O individual and we donate blood from the O individual to an A because the O individual doesn't have either antigen A or antigen B, what that means is the antibody against antigen B that this individual blood type A has will not be able to bind to the red blood cells of type O person.