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': 'Type of periodontitis which does not respond to therapy even after repeated treatments is: (OR) A child is having bone loss around molar and incisor region with pus discharge and calculus which cannot be treated by medications is suffering from? \nSelect and explain. \nA. Refractory periodontitis, B. Juvenile periodontitis, C. Rapidly progressive periodontitis, D. Chronic adult periodontitis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]