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 does not effect \nSelect and explain. \nA. Alveolar bone and enamel, B. Cementum and enamel, C. Epithelial attachment and gingiva, D. Periodontal ligament and Cementum', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]