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': 'Post-treatment apical periodontitis in an endodontically treated tooth is called as: \nSelect and explain. \nA. Recurrent apical periodontitis., B. Persistent apical periodontitis., C. Phoenix abscess., D. Chronic periapical abscess.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Persistent Apical Periodontitis\nPersistent apical periodontitis is a post-treatment apical periodontitis in an endodontically treated tooth', 'role': 'assistant'}]