Which of the Following Is Not a Component of Knudson's

Which of the following is not a component of Knudson's "two hit" hypothesis?

A) In the inherited cases of retinoblastoma, one of the inactivating mutations has been transmitted through the germ line.
B) Two mutational "hits" are required to knock out a gene that normally functions to suppress tumor formation.
C) A cancer develops only if a second mutation occurs in the somatic cells and if this mutation knocks out the function of the wild-type allele of the tumor suppressor gene.
D) All of these are true.
E) None of these are true.