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: Biochemistry
Glutathione requires which vitamin to act as antioxidant ? 
Select and explain. 
A. Vitamin E, B. Niacin, C. Vitamin C, D. Vitamin A
B: Niacin
Answer: B: Niacin 
Explanation: Ans. is 'b' i.e., Niacin