The correct answer is option 3: AB. The blood group AB is considered the universal recipient because individuals with this blood type can receive blood from any other blood group without experiencing adverse reactions. This is because the person`s blood contains both A and B antigens on the surface of their red blood cells, as well as neither A nor B antibodies in their plasma. Therefore, their immune system does not recognize any other blood type as foreign or incompatible, allowing them to safely receive transfusions from donors with blood types A, B, AB, or O. Conversely, individuals with blood type O are considered universal donors, as their blood lacks A or B antigens and corresponding antibodies, making it compatible with all other blood types.