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 the following is used to test the efficiency of sterilization in an autoclave? \nSelect and explain. \nA. Clostridium tetani, B. Bacillus stearothermophilus, C. Bacillus pumilus, D. Bacillus cereus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Autoclave: B. stearothermophillus\nHot air oven: Clostridium tetani nontoxigenic strain', 'role': 'assistant'}]