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': 'Which is the most likely to cause pulp necrosis? \nSelect and explain. \nA. Subluxation, B. Extrusion, C. Avulsion, D. Concussion', 'role': 'user'}, {'content': 'Answer: C \nExplanation: To have pulp space infection, the pulp must first become necrotic. This will occur in a fairly serious injury in which displacement of the tooth results in severing of the apical blood vessels.', 'role': 'assistant'}]