Agirl of Normal Stature Is Born to Two Parents with Achondroplasia

Agirl of normal stature is born to two parents with achondroplasia who have very short stature, especially disproportionately short arms and legs. What is theprobability (by Punnett square analysis) that any pregnancy this girl eventually has will result in the birth of an infant with achondroplasia if her partner also has normal stature?

A) Three out of four (75%)
B) Two out of four (50%)
C) One out of four (25%)
D) Zero out of four (0%)