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
Nagler reaction is shown by: 
Select and explain. 
A. Cl. difficle, B. Cl. perfringens, C. Cl. tetani, D. Cl. butryicum
B: Cl. perfringens
Answer: B: Cl. perfringens 
Explanation: Ans. is. b' i. e. Cl. perfringens