Which statement correctly describes AB blood in terms surface antigens and antibodies?

• A. Surface antigens A and B; anti-A antibodies
• B. Surface antigens A and B; neither anti-A nor anti-B antibodies
• C. Surface antigen B; anti-A antibodies
• D. Lacking both A and B antigens

Answer: (B)

AB blood type carries both A and B antigens on the surface of red blood cells, and its plasma contains no anti-A or anti-B antibodies. This combination is what makes the description correct: surface antigens A and B are present, and there are neither anti-A nor anti-B antibodies in the plasma. If anti-A antibodies were present, they would react with A antigens; if it were lacking both A and B antigens, that would describe type O blood. If only one antigen were present, that wouldn’t match AB’s expression of both.