This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Minerals, Subject name: Biochemistry
[{'content': 'Selenium is essential for the: \nSelect and explain. \nA. Glutathione peroxidase, B. Glutathione reductase, C. Glutathione synthetase, D. Glutathione hydroxylase', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. Glutathione peroxidasea. Glutathione peroxidase is a selenium containing enzyme which acts in synergism with vitamin E to protect against hydroperoxide free radical damage.b. First line of defense against hydroperoxide free radical damage is vitamin E (tocopherol) while the second line of defense is a selenium containing enzyme glutathione peroxidase.', 'role': 'assistant'}]