Answer:
Genotype of the child is (oo)
The mother (Ao)
The father (oo/Ao/Bo)
Explanation:
The woman is blood type A, but we know her genotype must be Ao (not AA) because she has a child with blood type O. That means the child got an o allele from each parent.
That's why dad must have at least one o. He could have three possible blood types (O, A, or B) with one genotype for each (oo, Ao, or Bo). The father cannot be blood type AB because then he couldn't give his child an o allele.