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 causes all except: \nSelect and explain. \nA. Leads to marginal gingivitis, B. Reversible in nature, C. Does not cause pocket formation, D. Alveolar crest height might be reduced', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Clinical features of TFO\xa0\n\nMobility (progressive)\xa0\nPain on chewing or\xa0percussion\xa0\nFremitus\xa0\nOcclusal prematurities/discrepancies\xa0\nWear facets in the presence of other clinical indicators\xa0\nTooth migration\xa0\nChipped or fractured tooth (teeth)\xa0\nThermal sensitivity\xa0\n\nKey notes :\nTFO hardly affects the gingival soft tissues.', 'role': 'assistant'}]