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
[{'content': 'Organism responsible for gas gangrene is/are: \nSelect and explain. \nA. Clostridium perfringens, B. Clostridium septicum, C. Clostridium histolyticum, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Clostridium perfringes is the main organism but other than this Clostridium oedematiens, Cl.septicum, Cl.histolyticum, Cl.bifermentans.', 'role': 'assistant'}]