This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'A defect in xeroderma pigmentosum \nSelect and explain. \nA. Nucleotide excision repair, B. Mismatch repair, C. Base excision repair, D. Double strand break repair', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Explanation:\nTypes of defects in DNA-repair systems and conditions associated', 'role': 'assistant'}]