This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Which type of glycoprotein is collagen? \nSelect and explain. \nA. O-linkage, B. N-linkage, C. GPI linkage, D. none', 'role': 'user'}, {'content': "Answer: A \nExplanation: O-glycosidic linkage: Mucin proteoglycans collagens Nuclear and cytosolic proteins N-Glycosidic linkage type: complex High mannose Hybrid GPI anchored: Acetylcholinesterase alkaline phosphatase Decay-accelerating factor 5'-nucleotidase Thy 1 antigen Variable surface glycoprotein Reference: Harpers illustrated biochemistry 31st edition pg549", 'role': 'assistant'}]