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: Microbiology
[{'content': 'Treatment for acute attack of Hereditary angioneurotic edema \nSelect and explain. \nA. Ecallantide, B. Icatibant, C. Danazol, D. C1 INH Concentrate', 'role': 'user'}, {'content': 'Answer: D \nExplanation: C1\xa0INH Concentrate - Treatment of choice.', 'role': 'assistant'}]