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': 'Grinspan syndrome is associated with \nSelect and explain. \nA. Leukoplakia, B. Lichen planus, C. Aphthous ulcer, D. Oral submucous fibrosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]