This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Death and postmortem changes, Subject name: Forensic Medicine
[{'content': 'For biochemical analysis vitreous in sent in - \nSelect and explain. \nA. Hydrochloric acid, B. Phenol, C. Formalin, D. Fluoride', 'role': 'user'}, {'content': 'Answer: D \nExplanation: 10 mg fluoride in every 1 ml of vitreous humor is added for preservation in analysis of alcohol, cocaine, cyanide and CO. Dr. Narayana Reddys Synopsis of Forensic Medicine & Toxicology 27 th edition pg. 62.', 'role': 'assistant'}]