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': 'Enamel fracture without tooth structure loss or incomplete enamel fracture results from \nSelect and explain. \nA. Concussion, B. Avulsion, C. Subluxation, D. Enamel infraction', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]