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': 'Trauma from occlusion refers to \nSelect and explain. \nA. Occlusion which causes trauma, B. Abnormally of the periodontium, C. Changes in periodontium due to occlusal forces, D. Inflammation of periodontium', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]