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': 'Itchy polygonal violaceous (itchy/prusitic) palpules seen rn \nSelect and explain. \nA. Psoriasis, B. Pemphigus, C. Lichen planus, D. Pitriasios rosea', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C. i.e. Lichen planus', 'role': 'assistant'}]