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
Substance commonly used for tissue preservation commonly is: 
Select and explain. 
A. Ethyl alcohol, B. Formalin, C. Sodium Chloride, D. Normal Saline
B: Formalin
Answer: B: Formalin 
Explanation: Formalin