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': 'A 30 years old male presented with silvery scales on elbow and knee, that bleed on removal. The probable diagnosis is: \nSelect and explain. \nA. Pityriasis, B. Seborrhoeic dermatitis, C. Psoriasis, D. Secondary syphilis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Psoriasis', 'role': 'assistant'}]