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
Which of the following prevent lens opacity by free radical scavening? 
Select and explain. 
A. Glutathione, B. Catalase, C. Vitamin A, D. Vitamin E
A: Glutathione
Answer: A: Glutathione 
Explanation: Glutathione prevent lens opacity by free radical scavening.