This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'The main causative organism of Gas gangrene is \nSelect and explain. \nA. Bacillus anthrax, B. Cloastridium tetani, C. Clostridium defficile, D. Clostridium perfringens', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Gas gangrene is caused by Clostridium PerfringensRef: Harrison&;s Principles of Internal Medicine; 19th edition; Chapter 156; Infections of the Skin, Muscles, and Soft Tissues', 'role': 'assistant'}]