Answer:
The correct answer would be 25 percent.
It is the case when both the parents are heterozygous for the trait that is, both are Rr in genotype.
Thus, both the parents would produce two types of gametes one of which contain R and the other one would contain r.
The cross would result in the production of the offspring with three types of genotypes; RR, Rr, and rr.
The three genotypes would be present in the ration 1 (RR): 2 (Rr): 1 (rr).
Thus, only one out of four would be Rh- in phenotype. Hence, only 25 percent is the probability that the offspring would not be able to receive blood from either parent.
According to the Punnett square, it is likely that 1 out of 4 offspring will be homozygous recessive or Rh-. That means there is a 25% that offspring will be Rh- and will not be able to receive blood from either parent.
