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': 'Which of following clostridia is non-invasive: \nSelect and explain. \nA. Clostridium novyi, B. Clostridium botulinum, C. Clostridium perfringens, D. Clostridium tetani', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is. 'b' i. e. Clostridium botulinum", 'role': 'assistant'}]