A Man Inherited a Chromosome with a Deletion That Removes

A man inherited a chromosome with a deletion that removes a tumor-suppressor gene.The protein encoded by this gene normally functions in DNA damage repair.Which series of events would be most likely to lead to cancer?

A) Loss-of-heterozygosity of the tumor-suppressor gene followed by driver mutations in two different proto-oncogenes
B) A loss-of-function mutation in a proto-oncogene followed by a gain-of function mutation in a tumor-suppressor gene
C) Loss-of-heterozygosity of the tumor-suppressor gene followed by passenger mutations in several genes of unknown function
D) A gain-of-function mutation in a proto-oncogene followed by a chromosomal duplication of a region including a tumor-suppressor gene that functions the G₁-to-S checkpoint