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
For biochemical analysis vitreous in sent in: 
Select and explain. 
A. Hydrochloric acid, B. Phenol, C. Formalin, D. Fluoride
D: Fluoride
Answer: D: Fluoride 
Explanation: D i.e. Fluoride