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: Forensic Medicine
[{'content': 'C.S.F. is required to be preserved in - \nSelect and explain. \nA. Alcoholic poisoning, B. Arsenic poisoning, C. Copper poisoning, D. Organophosphorus poisoning', 'role': 'user'}, {'content': 'Answer: A \nExplanation: For alcohol poisoning, blood,\xa0CSF,\xa0vitreous humor and urine are preserved with using fluoride as a preservative.', 'role': 'assistant'}]