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 60 years old man presented with itchy tense blisters on normal looking skin and uicarial rash. Investigation done for the diagnosis: \nSelect and explain. \nA. Direct immunofluorescence, B. Indirect immunofluorescence, C. Histopathology, D. Cytopathology', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. a. Direct immunofluorescence A 60 years old man presented with itchy tense blisters on normal looking skin and uicarial rash. This patient is suffering from pemphigoid. Investigation done for the diagnosis direct immunofluorescence.', 'role': 'assistant'}]