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
One of the most serious complication of urticaria is: 
Select and explain. 
A. Anaphylactic shock, B. Heart block, C. Cerebral edema, D. Septicemia
A: Anaphylactic shock
Answer: A: Anaphylactic shock 
Explanation: None