Final answer:
The probability that the Rh-negative mother will react to her second baby's blood when the father is homozygous dominant for the Rh-factor allele is 0% probability (B).
Step-by-step explanation:
If the father is homozygous dominant for the Rh-factor allele, the probability that the Rh-negative mother will react to her second baby's blood is 0% probability (B). When one parent is homozygous dominant for the Rh-factor allele, the trait will only show in the offspring if the other parent is also a carrier. Since the mother is Rh-negative, she does not carry the Rh-factor allele, so there is no chance of an immune reaction to the second baby's blood.