Answer:
If the child is B, and the mother is A: then the possible genotype of the father should be blood group AB, with genotype AB, co-dominant while the possible genotype of the mother should be AA. AO. Consequently, The child ‘s blood group should be A, AB, B. Thus the man who belongs to blood group AB is the father.
The man of the blood group O, cannot be the father, since his blood group is O (universal donor), genotype is OO, then the possible blood type of the child are either A or O, with the woman(AA, AO), but not AB that the child has.
This is because the possible genotype of the O group man can only be OO and that of that woman AO, AA, so no chance of having a child of B group.
Hence AB father, fathered the child.
Step-by-step explanation: