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': 'In WHO classification of periradicular diseases code no. KO4.4 represents \nSelect and explain. \nA. Acute apical periodontitis, B. Chronic apical periodontitis, C. Periapical abscess, D. Radicular cyst', 'role': 'user'}, {'content': 'Answer: A \nExplanation: WHO classification of periradicular diseases\n\nKO4.4….acute apical periodontitis\nKO4.5…chronic apical periodontitis\nKO4.6…periapical abscess with sinus\nKO4.7…periapical abscess without sinus\nKO4.8….radicular cyst', 'role': 'assistant'}]