One hereditary disease in humans, called xeroderma pigmentosum (XP), makes homozygous individuals exceptionally susceptible to UV-induced mutation damage in the cells of exposed tissue, especially skin. Without extraordinary avoidance of sunlight exposure, patients soon succumb to numerous skin cancers. -Given the damage caused by UV, the kind of gene affected in those with XP is one whose product is involved with
A) mending of double-strand breaks in the DNA backbone. B) breakage of cross-strand covalent bonds. C) the ability to excise single-strand damage and replace it. D) the removal of double-strand damaged areas. E) causing affected skin cells to undergo apoptosis.