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: Dental
[{'content': 'Bacteria used to check the working efficiency of an autoclave is: \nSelect and explain. \nA. Bacillus stearothermophilus, B. Bacillus subtilis, C. Campylobacter, D. Bacillus tardinicus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: There are three indicators that may be used to detect the efficacy of the autoclave process:\xa0\n\nPhysical: Pressure and temperature recording devices.\nChemical:\xa0Indicators that change color after being exposed to specific temperatures, such as temperature-sensitive tape. The color change upon exposure to the given temperature.\nBiological: Bacillus stearothermophilus spores are used, due to its resistance to heat, for the testing that measures the biological performance of the autoclave process.', 'role': 'assistant'}]