This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Microbiology
[{'content': 'Biological indicator for determining efficacy of autoclaving is \nSelect and explain. \nA. Pseudomonas aeruginosa, B. Clostridium perfringenes, C. Bacillus stearothermophilus, D. Salmonella typhi', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Sterilization control METHOD Sterlization control Hot air oven Autoclave Filtration Ionizing radiation (cold sterilization) Ethylene oxide Plasma sterilization Clostridium tetani non toxigenic strain, B.subtilis, sub sp. niger B.Stearothermophillus Brivundimonas dimunata B. Pumilus B.Globigi B.Stearothermophillus', 'role': 'assistant'}]