Answer: D. 100%.
Step-by-step explanation:
Cystic Fibrosis is an Autosomic Recessive Disorder. The family pedigree chart shows that the Mother is a Carrier (Aa) and the Father has the disease (aa).
The offspring of both parents is affected by 100%.
75% have the disease (2 female, 1 male)
25% are carriers (1 male)