Cystic Fibrosis Is Caused by the Allele F, Which Is

Multiple Choice

Cystic fibrosis is caused by the allele f, which is completely recessive to the normal dominant allele F. Consider a couple with the genotype Ff. What is the chance that their second child will develop cystic fibrosis?

A) 25%
B) 50%
C) 75%
D) 100%
E) It depends on which alleles were inherited by their first child.