Use the following information to answer the questions below.
A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative.Rh positive is a trait that shows simple dominance over Rh negative and is designated by the alleles R and r,respectively.A third gene for the MN blood group has codominant alleles M and N.
-Which of the following is a possible partial genotype for the son?