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': '"Citron bodies" are formed by? \nSelect and explain. \nA. Clostridium welchii, B. Clostridium oedematiens, C. Clostridium septicum, D. Clostridium histolyticum', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Citron bodies - Boat or leaf-shaped pleomorphic bacilli with irregular staining on gram stained smears in a suspected case of gas gangrene suggests Cl. septicum', 'role': 'assistant'}]