This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli), Subject name: Microbiology
[{'content': 'Which of the following is non-motile? \nSelect and explain. \nA. C histolyticum, B. C perfringens, C. C ramosum, D. C.botulinum', 'role': 'user'}, {'content': "Answer: B \nExplanation: Clostridia are Gram positive, obligate anaerobes , spore forming (bulging) bacilli. All are motile by peritrichous flagellae except Cl.perfringens and Cl.tetani type VI. Motility - 'stately' They are noncapsulated except C. perfringens and C. butyricum.", 'role': 'assistant'}]