This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lens, Subject name: Ophthalmology
[{'content': 'Which does not handle free radicals inside lens- \nSelect and explain. \nA. Vitamin A, B. Vitamin C, C. Vitamin E, D. Catalase', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Emzymatic antioxidant mechanisms :- Reduced glutathioe (most impoant), glutathione peroxidase, superioxide dismutase, catalase. Non-enzymatic defence mechanisms :- Vitamin C, Vitamin E, and possibly carotenoids. Ref: Various textbooks.', 'role': 'assistant'}]