Final answer:
If one parent has type O blood, the possible genotypes of the other parent could be IAi or IAIA, resulting in the child having type A blood.
Step-by-step explanation:
Type A blood is determined by the presence of the A antigen on red blood cells and is inherited through the IA allele. Type O blood, on the other hand, does not have any antigens and is inherited through the ii genotype. If one parent has type O blood, it means they have the ii genotype. So, the other parent's possible genotypes could be IAi (heterozygous for the A allele) or IAIA (homozygous for the A allele). These genotypes would result in the child having type A blood.