In the ABO blood group system (a variation of dominance known as codominance), what genotype would a person with type AB blood have?

• A. $I^A{i}_{\mathrm{}}$
• B. $I^A{I}^B$
• C. $I^B{i}_{\mathrm{}}$
• D. $i_{\mathrm{}}{i}_{\mathrm{}}$

Answer: (B)