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': 'A 15-year-old-boy suffers from vesiculating painful ulcers, there is also oral temperature of 103° F since 3 days and lymphadenopathy. The most likely diagnosis is: \nSelect and explain. \nA. Herpes zoster, B. Acute herpetic gingivostomatitis, C. Major apthae, D. Recurrent aphthae', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]