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: Pathology
[{'content': "Nikolsky's sign is positive in: \nSelect and explain. \nA. Pemphigus., B. Familial benign chronic pemphigus., C. Epidermolysis bullosa., D. All of the above.", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]