Phenylketonuria (PKU)is an Inherited Disease Caused by a Recessive Allele

Phenylketonuria (PKU)is an inherited disease caused by a recessive allele. If a woman and her husband, who are both carriers, have three children, what is the probability of each of the following?
A)All three children are of normal phenotype.
B)One or more of the three children have the disease.
C)All three children have the disease.
D)At least one child is phenotypically normal.
(Note: Remember that the probabilities of all possible outcomes always add up to 1.)