This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of carbohydrate, Subject name: Biochemistry
[{'content': 'Which mucopolysaccharides does not contain uronic acid? \nSelect and explain. \nA. Hyaluronic acid, B. Chondroitin sulfate, C. Dermatan sulfate, D. Keratan sulfate', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]