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': 'Benzidine test is done to detect: PGI 07 \nSelect and explain. \nA. Semen, B. Blood, C. Bile, D. Saliva', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Blood', 'role': 'assistant'}]