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: Surgery
[{'content': 'Of the following in which condition local anesthesia is ineffective? \nSelect and explain. \nA. Edema, B. Localized infection, C. Hematoma, D. Anemia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]