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': 'Polygonal violaceous , well defined flat topped ,itchy papules are the primary lesions of \nSelect and explain. \nA. Lichen planus, B. Phemphigus vulgaris, C. Lupus erythematous, D. Psoriasis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Lichen planus lesions are classically violaceous well defined polygonal itchy papules.', 'role': 'assistant'}]