Answer:
The correct option is C) Dd and Dd
Explanation:
To explain the answer, lets make a punnet square with a cross between Dd and Dd.
D d
D DD Dd
d Dd dd
As deafness is a recessive trait, this means that both the alleles in a person should be same and recessive for that trait to occur in the phenotype. A cross between heterozygous carriers show that there will be a 25% probability that the offsprings produced will get the recessive alleles and hence they will be deaf. 50% of the offsprings will have the chance to be carriers like their parents. And there willbe a 25% chance that they will have normal homozygous alleles.