If there are two different alleles for a trait, this means t<span>he trait could show up in two different forms.</span>
Because there always needs to be something that starts it off. Eg: If there was no grass, there would be no animals.
I'm pretty sure that its the 3rd answer
It can be possible because the mother can present B blood phenotype. This opens the possibility of she having an heterozygous genotype of I^b i or I^b I^b which are dominant over the genotype of the O type father.
