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: Dental
[{'content': 'A patient presents with erythematous scaly lesions on extensor aspect of elbows and knee. The clinical diagnosis is got by – \nSelect and explain. \nA. Auspitz sign, B. KOH smear, C. Tzanck smear, D. Skin biopsy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Erythematous scaly lesions on extensor aspect of elbow and knee favours the diagnosis of Psoriasis.\nThe clinical diagnosis of psoriasis can be made by demonstrating Auspitz sign.\nIt is a characteristic finding of psoriasis in which removal of scale leads to pinpoint bleeding.', 'role': 'assistant'}]