If a type-A person contains anti-M in their serum, what might their reverse grouping type as?

Question

Quizplus · Accepted Answer

Anti-M is not typically found in the serum of individuals with ABO blood types A, B, or AB, so a type-A person with anti-M in their serum is likely blood type O. This is because individuals with blood type O lack A and B antigens on their red blood cells and thus do not produce antibodies against these antigens.

If a Type-A Person Contains Anti-M in Their Serum, What