Answer:
Heterozygous A: AO (remember, O type blood is a recessive allele. It's masked by A)
Heterozygous B: BB (h0m0zygous)
AO x BB --> AB, BO
Therefore, the genotypes of their offspring will be 1 AB to 1 BO, while the phenotypes will be 1 AB blood to 1 B blood.
I hope this answer helps you find what your looking for! :)
