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': 'Location of Keratan sulfate 1 is \nSelect and explain. \nA. Skin, B. Bone, C. Cornea, D. Lung', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Keratan sulfate I was originally isolated from the cornea, while keratan sulfate II came from cailage. In the eye, they lie between collagen fibrils and play a critical role in corneal transparency. Changes in proteoglycan composition found in corneal scars disappear when the cornea heals. Reference: Harper&;s Biochemistry; 30th edition; Chapter 50; The Extracellular Matrix', 'role': 'assistant'}]