D would be the answer because it’s more logical in a way than the others.
In order to determine the results from a father who is homozygous recessive for the tongue rolling trait, T, and a mother who is heterozygous for the trait, a Punett square can be used to determine both the resulting genotype (allele combination) and phenotype (observable characteristics). The results are 50% Tt and 50% tt. Thus, the cross would result to 1:1 ratio of tongue rolling to non-tongue rolling offsprings.
The answer is Nitrification.
