This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: vitamins, Subject name: Biochemistry
[{'content': 'All of the following are watersoluble radical trapping antioxidants except? \nSelect and explain. \nA. Ascorbate, B. Carotenes, C. uric acid, D. Polyphenols', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ascorbate, uric acid, and a variety of polyphenols derived from plant foods act as water-soluble radical trapping antioxidants. Ubiquinone and carotenes similarly act as lipid-soluble radical-trapping antioxidants in membranes and plasma lipoproteins. Reference: Harpers illustrated biochemistry 30th edition', 'role': 'assistant'}]