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': 'The gingiva is attached to the tooth by: \nSelect and explain. \nA. Lamina propria, B. Periosteum, C. Epithelial attachment, D. Gingival fibers', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]