A Baby Boy Is Born with Six Toes (Polydactyly) on His

Multiple Choice

A baby boy is born with six toes (polydactyly) on his right foot, a trait that neither parent has but one that the paternal grandfather has. What is the bestexplanation for this occurrence?

A) The baby's grandfather is really his father.
B) The baby inherited a recessive allele for this trait from each parent.
C) The father's phenotype results from incomplete penetrance of a dominant allele.
D) The baby's phenotype demonstrates a higher level of expressivity than his father's phenotype.