This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'Aggrecan in \nSelect and explain. \nA. Receptor over platelets, B. A molecule present in osteoid tissue, C. Granules in leukocytes, D. Important component of cartilage', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Aggrecan is the major proteoglycan component of cartilage. It is composed of several glycosaminoglycans (hyaluronic acid, chondroitin sulfate and keratin sulfate) and both link and core proteins.', 'role': 'assistant'}]