This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Microbiology (Sterilization and Bacterial Genetics), Subject name: Microbiology
[{'content': 'For hot air oven holding time at 160degC is \nSelect and explain. \nA. 2 hour, B. 15 minutes, C. 30 minutes, D. 20 minutes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Recommended holding time of hot air oven At 160 C is 1.5-2 hour At 170 C for 60 min At 180 C is 30 min', 'role': 'assistant'}]