To which blood group do universal recipients belong?

Universal recipients belong to blood group AB. Blood groups are classified based on the presence or absence of certain antigens on the surface of red blood cells. These antigens can trigger an immune response if they are not compatible with a person's blood type. Blood group AB has both A and B antigens on the surface of their red blood cells, but does not have antibodies against either A or B antigens in their plasma. This means that they can receive red blood cells from any blood type (A, B, AB, or O) without triggering an immune response, making them universal recipients. However, blood group AB individuals can only donate blood to other AB individuals, as their blood contains both A and B antigens.