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': 'ABO antigens is not found in: AIIMS 09; NEET 14 \nSelect and explain. \nA. CSF, B. Semen, C. Sweat, D. Saliva', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. CSF', 'role': 'assistant'}]