This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Clostridium, 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 > d' i.e., Clostridium botulinum > Clostridium tetani o Their invasive power is different in different species :Cl. botulinumo Virtually noninvasive and noninfectious.o Botulism is due to ingestion of preformed toxin.Cl. tetanio Has little invasive power and is confined to the primary site of lodgemento Tetanus results from the action of the potent exotoxinGas gangrene clostridiao Invasive and can spread along tissue.o Gas gangrene (clostridial myonecrosis) is caused by Cl perfringens/welchii, Cl septicum, Cl novyi and Cl histolyticum.", 'role': 'assistant'}]