Final answer:
O blood type can have an antigen mismatch with A, B, or AB antigens due to the presence of anti-A and anti-B antibodies in type O blood.
Step-by-step explanation:
The only antigen mismatch that O blood type can have is with either A, B, or AB antigens because type O blood lacks any A or B antigens. People with type O blood have both anti-A and anti-B antibodies, which would react with any A or B antigens introduced into the body through a transfusion. Therefore, while individuals with type O blood can donate to any ABO blood type due to the absence of antigens that could cause an immune reaction, they can only receive type O blood to avoid an antigen-antibody reaction that could lead to hemolysis.