Final answer:
Three-fourths of the offspring will show the dominant phenotype and one-fourth will show the recessive phenotype.
Step-by-step explanation:
The Punnett square is a tool used to predict the potential offspring of a cross. In this case, the Punnett square indicates that the potential offspring will have two possible phenotypes - the dominant phenotype and the recessive phenotype. In the given Punnett square, there are 3 squares with the dominant genotype (DD, DD, and Dd) and 1 square with the recessive genotype (dd). Therefore, three-fourths (75%) of the offspring will show the dominant phenotype, while one-fourth (25%) will show the recessive phenotype. So, the correct answer is option D: Three fourths of the offspring will show the dominant phenotype and one fourth will show the recessive phenotype.