Answer:
IBi0
Step-by-step explanation:
We look at the child's genotype (lAi0).
We know that the blood type's genotype has 2 genes, one from the mother and one from the father.
If the genotype is lAi0 and one gene is, let's say, from mother (lA), we know exactly that the other gene is from father (i0).
So, father's genotype is lBi0 (a).
