Why Do People with Inheritable High-Risk Mutations Develop Cancer at an Earlier

Why do people with inheritable high-risk mutations develop cancer at an earlier age?

A) People who have inherited high-risk mutations start life with at least one predisposing mutation,so they require fewer additional mutations.
B) People who have inherited high-risk mutations always have other environmental risk factors putting them at higher risk for developing cancer at a younger age.
C) People with inheritable high-risk mutations start expressing the mutated genes at a younger age.
D) The inherited mutations cause new mutations to occur more easily.
E) All the above.