Context: This passage describes the coat graying trait in horses:
Your hair may turn gray or white as you grow older. Some horses go through a similar process called coat graying as they age. These horses are usually a darker color, such as brown or black, when they are born. Over time, the hairs of their coats lose their original color and become gray or white.
In a group of horses, some individuals have coat graying and others do not. In this group, the gene for the coat graying trait has two alleles. The allele for having a graying coat (G) is dominant over the allele for not having a graying coat (g).
This Punnett square shows a cross between two horses.
What is the expected ratio of offspring that have coat graying to offspring that do not have coat graying? Choose the most likely ratio.
A. 3:1
B. 0:4
C. 2:2
D. 4:0
E. 1:3
Identify the correct option from the choices provided and respond with the letter of the correct option.

D