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: Medicine
[{'content': 'One of the most serious complication of urticaria is: \nSelect and explain. \nA. Anaphylactic shock, B. Heart block, C. Cerebral edema, D. Septicemia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]