Answer:
Blood groups A,B, AB and O are determined by the presence of antigen A and B. O blood group does not have any antigen and that is why person with O blood group is universal donor.
The child inherits one allele each from either parent. Thus all the children will receive recessive allele (i) from mother and either IA or IB from the father. The woman in question has O blood group and has genotype (ii).
Her husband has AB blood group and thus has genotype IA IB.
-Hops
