Exposure to the UV Radiation in Sunlight Causes DNA Changes

Multiple Choice

Exposure to the UV radiation in sunlight causes DNA changes in skin cells. Why are these changes more harmful when they occur in an individual with xeroderma pigmentosum (XP) than in an individual who does not have this disorder?

A) XP individual's DNA replication machinery incorporates more incorrect nucleotides in new DNA strands than occur in non-XP individuals.
B) Compared to XP individuals, non-XP individuals produce more UV protecting pigments.
C) XP individuals have significantly more thymine's in their DNA than non-XP individuals do
D) Compared to XP individuals, non-XP individuals have more effective nucleotide excision repair enzymes.