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
Which of the following is not a feature of anaphylaxis? 
Select and explain. 
A. Delayed reaction, B. Immediate reaction, C. Passive transfer by serum, D. None of the above
A: Delayed reaction
Answer: A: Delayed reaction 
Explanation: None