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 is not antioxidant? 
Select and explain. 
A. Superoxide dismutase, B. Catalase, C. Coagulase, D. Glutathione peroxidase
C: Coagulase
Answer: C: Coagulase 
Explanation: Superoxide dismutase, Glutathione peroxidase, catalase are the key enzymatic antioxidants by which free radicals that are produced during metabolic reactions are removed.