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': 'Which of the following specimen shows blue white colour in UV rays? \nSelect and explain. \nA. Semen, B. Blood, C. Pus, D. Leucorrhoea', 'role': 'user'}, {'content': 'Answer: A \nExplanation: After a month seminal stains becomes yellow to brown. When examined under filtered ultraviolet light, they show a fluorescence of a bluish-white colour, which is not specific as other albuminous material such as nasal, leucorrhoeal discharges and detergents also fluoresce. Ref: The Essentials of Forensic Medicine and Toxicology by K S Reddy, 27th edition, Page 369', 'role': 'assistant'}]