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: Biochemistry
[{'content': 'UV light causes mutation in cells by \nSelect and explain. \nA. Formation of pyrimidine dimers, B. Ionisation of molecules, C. Double stranded DNA break, D. Chromosomal instability', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]