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
Organism responsible for gas gangrene is/are: 
Select and explain. 
A. Clostridium perfringens, B. Clostridium septicum, C. Clostridium histolyticum, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Clostridium perfringes is the main organism but other than this Clostridium oedematiens, Cl.septicum, Cl.histolyticum, Cl.bifermentans.