Which of the following is true for disease in families A and B ?

Options

A. In family A , both the parents are carrier for the sex - linked recessive disorder.
B. In family B , both he parents are homozygous for the sex - linked dominant disorder.
C. In family B , both the parents are heterozygous for an autosomal recessive disorder.
D. In family A , both the parents are heterozygous for an autosomal recessive disorder.

Answer

D