A man woman are both affected by vitamin D resistance rickets, which is a sominant sex-linked allele. All of the female of springs of this couple are affected with rickets but some of the male offsprings are not. What are the genotypes of the parents ?

Options

A. Both are homozygous for the trait.
B. Two woman has two dominant alleles and man han one dominant allele.
C. Both parents have only recessive alleles.
D. Each parent has only one dominant allele.

Answer

D