Answer:
Option D
Step-by-step explanation:
Given
Straight thumbs are dominant to hitchhiker's (bent) thumbs.
Let straight thumbs be represented by "S" and bent thumbs be represented by "s"
Genotype of homozygous dominant female is SS
Genotype of heterozygous male is Ss
Cross between SS and Ss will produce following offspring
SS * Ss
SS, SS, Ss, Ss
All the off spring have straight thumb.
Thus, option D is correct