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': 'Dental and periodontal infections can pose a severe risk to patients under \nSelect and explain. \nA. Chemotherapy, B. Radiotherapy, C. Ozone therapy, D. Water therapy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]