Just want to double check please...

Susie has two children, Mary and Jake. Given that Susie has Alzheimer’s and
there’s a 25% chance that she passed the Alzheimer’s gene onto her
offspring, what is the probability of BOTH Mary and Jake developing
Alzheimer’s, based on genetics alone?
a) 25%
b) 50%
c) 5%
d) 6.25%
e) 0%

Pr ( A and B) = Pr (A) * Pr (B)
= 0.25 * 0.25

answer d) = 0.0625