Which statement describes type AB antibodies?

• A. Anti-A antibodies only
• B. Anti-B antibodies only
• C. Neither anti-A nor anti-B antibodies
• D. Both anti-A and anti-B antibodies

Answer: (C)

Type AB individuals have red blood cells that carry both A and B antigens, but their plasma contains no antibodies against A or B. Because these antigens are present during immune development, tolerance develops to both, so the person does not form anti-A or anti-B antibodies. That makes the statement describing them as having neither anti-A nor anti-B antibodies the best answer. This lack of antibodies against A and B explains why AB individuals can receive RBCs from any ABO type without antibody-mediated hemolysis, unlike other groups that do have anti-A or anti-B antibodies in their plasma.