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': 'Florence test done on dry seminal stain shows dark-brown crystals due to: September 2012, March 2013 (e) \nSelect and explain. \nA. Sperm, B. Dye, C. Spermine, D. Choline', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D i.e. Choline Florence test of semen depends on choline', 'role': 'assistant'}]