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': 'Acute herpetic gingivostomatitis \nSelect and explain. \nA. occur in children and young adults, B. occur only in young children, C. occur in only adults, D. all of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]