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': 'Epidermal Bullosa Acquisita is characterized by \nSelect and explain. \nA. Immunoglobulins against collagen 7, B. IgA against BP2, C. Immunoglobulins against BP2, D. Immunoglobulins against Dsg-1', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Epidermal Bullosa Acquisita : Immunoglobulins against collagen 7\nEpidermal Bullosa Dystrophica : absence of collagen 7', 'role': 'assistant'}]