Punnet squares use mathematical possibility to help predict the genotype and phenotype combinations in genetic crosses. Select the steps below describe how to construct Punnet squares. A. All possible combinations of Alleles in the gametes produced by one parent a written along the top edge of the square. B all possible combinations of Alleles The other parent written along the left edge of the square. C. All possible genotypes a written inside the boxes when is the square as they might appear in the offspring. D. All possible combinations of phenotypes are written above edges of the square