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: Pathology
[{'content': 'Oral ulcers which occurs in groups, persist for about 6 weeks and leave scars on healing are: \nSelect and explain. \nA. Recurrent aphthous major, B. Recurrent aphthous minor, C. Recurrent herpetiform ulcers, D. Acute herpetic gingivostomatitis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]