Two Unaffected Parents Each Have a Parent with the Same

Multiple Choice

Two unaffected parents each have a parent with the same recessive condition and they want to know the chances that they will have a child who has the condition. What do you tell them?

A) the chance that their child will be affected is 0%
B) the chance that their child will be affected is 100%
C) the chance that their child will be affected is 25%
D) the chance that their child will be affected is 75%
E) the chance that their child will be affected is 50%