In an emergency, a person with type B blood can safely donate blood to individuals with blood type AB or B. This compatibility is due to the presence of B antigens on the red blood cells of both type B and AB individuals, ensuring compatibility and reducing the risk of adverse reactions. However, it’s important to note that while type B blood can be transfused to AB and B recipients, caution is exercised to match blood types as closely as possible to minimize risks. Blood type compatibility is crucial in transfusion medicine to prevent adverse immune reactions, so thorough testing and matching are typically performed before transfusions.