Which one of the following could NOT be the genotypes of the...

Blood group O requires the genotype $I^0 I^0$.

For a child to have blood group O, both parents must contribute an $I^0$ allele.

Parents with the genotype $I^A I^B$ do not possess the $I^0$ allele. Therefore, they can only produce offspring with blood groups A, B, or AB (genotypes $I^A I^A$, $I^B I^B$, or $I^A I^B$).

Thus, parents with genotypes $I^A I^B\ \text{Rh}^{+ve}$ and $I^A I^B\ \text{Rh}^{+ve}$ cannot have a child with blood group O.

Answer: $I^A I^B\ \text{Rh}^{+ve}$ and $I^A I^B\ \text{Rh}^{+ve}$