ABO Blood Type Inheritance

In humans, the ABO blood group system exhibits codominance and multiple alleles, where three primary alleles exist: IA, IB, and i. The IA allele produces antigen A, the IB allele produces antigen B, and the i allele does not produce any antigens. When an individual possesses both IA and IB alleles, their blood type is AB, meaning that both antigens are expressed.

Consider a couple where one parent has blood type A (genotype IAi) and the other has blood type B (genotype IBi). What are the possible blood types of their offspring?