This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Classification of carbohydrate, Subject name: Biochemistry
[{'content': 'Which glycosaminoglycan is present in cornea ? \nSelect and explain. \nA. Dermatan sulfate, B. Chondroitin Sulfate, C. Hyaluronic acid, D. Keratan Sulfate', 'role': 'user'}, {'content': 'Answer: D \nExplanation: option d : Keratan sulafte Glycosaminoglycan in cornea: Keratan sulafte (KS) >>> Chondroitin sulfate (CS) & Dermatan sulfate (DS) All are present in cornea but KS is in maximum amount Immunohistochemistry revealed the presence of both high- and low-sulphated epitopes of KS, as well as DS, throughout the cornea CS only in the peripheral cornea before the limbus. Keratan sulfate is also responsible for corneal transparency. Keratan Sulfate-I is present in cornea while Keratan Sulfate-II is present in cailages.', 'role': 'assistant'}]