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: Skin
[{'content': "Max. Joseph's space is a histopathological feature of: \nSelect and explain. \nA. Psoriasis vulgaris, B. Lichen plan us, C. Pityriasis rosea, D. Parapsoriasis", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Lichen plan us', 'role': 'assistant'}]