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: Pathology
Which of the following enzyme protects the brain from free radical injury? 
Select and explain. 
A. Hydroxylase, B. Myeloperoxidase, C. Superoxide dismutase, D. Mono Amine Oxidase
C: Superoxide dismutase
Answer: C: Superoxide dismutase 
Explanation: There are several cellular mechanisms by which cells remove free radicals and thereby protect organs from injury. Superoxide is a free radical, it is inactivated by superoxide dismutase (SOD) and is conveed into hydrogen peroxide. There are two types of superoxide dismutases such as manganese SOD located in the mitochondria and copper zinc SOD located in the cytosol. Ref: Robbins Pathologic Basis of Diseases, 5th Edition, Page 12-13