This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
[{'content': 'All are sources of free radicals except - \nSelect and explain. \nA. Fentons reaction, B. Glutathione, C. Myeloperoxidase, D. Nitric oxide', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Harshmohan textbook of pathology 7th edition. Reduced glutathione protects RBCs against oxidant stress produced by the oxygen free radicals. MPO, Fenton reaction produce oxygen free radicals. NO is a free radical..', 'role': 'assistant'}]