This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Free Radical Injury, Subject name: Pathology
Which of the following is a free radical scavenging enzyme? 
Select and explain. 
A. Myeloperoxidase, B. Glutathione peroxidase, C. NADPH oxidase, D. Protease
B: Glutathione peroxidase
Answer: B: Glutathione peroxidase 
Explanation: Elimination of free radical occur multiple mechanism:- 1.Antioxidant: (Glutathione and vitamin A, C, E) 2.Enzymes:- (i) Superoxide dismutase(mitochondria) O2-H2O (ii) Glutathione peroxidase (mitochondria) (iii) Catalase (Peroxisome): H2O2-O2 and H2O (glutathione independent). 3. Metal Carrier protein (Transferrin/Ceruloplasmin). Destruction of phagocytose material:- Oxygen dependent killing is most effective mechanism.