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: Dental
[{'content': "Which of the following substances play a major role in regulating cell-cell and cell-matrix interaction in cementum? \nSelect and explain. \nA. Sharpey's fibers, B. Intrinsic fibers, C. Proteoglycans, D. Phosphoproteins", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]