13. Suppose a trait is determined by a dominant allele ( A ) versus a recessive allele (a). After crossing a dominant phenotype to a recessive phenotype, a scientist found that half (1/2) of the progenies displayed the dominant phenotype and half (1/2) of the progenies displayed the recessive phenotype. What can be concluded from the experiment? (A) The genotype of the dominant parent is AA. (B) The genotype of the dominant parent is Aa (C) The phenotype is X-linked. (D) The data is inconclusive to tell the genotype of the dominant parent.