This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Dental
[{'content': 'A Patient came with h/o itchy tense blisters whose roof settled as above. Shows big blisters on forearm which have subsided with the roof sticking to the floor without much damage. Diagnosis is \nSelect and explain. \nA. Bullous pemphigoid, B. Pemphigus vulgaris, C. Dermatitis herpetiformis, D. Steven Johnson syndrome', 'role': 'user'}, {'content': 'Answer: A \nExplanation: .', 'role': 'assistant'}]