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
[{'content': 'Gas gangrene is due to -a) Alpha toxinb) Theta toxinc) Beta toxind) Delta toxine) Epsilon toxin \nSelect and explain. \nA. ac, B. ab, C. ad, D. bc', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]