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': 'Filters used to purify air in biological safety cabinets? \nSelect and explain. \nA. HEPA (High efficiency particulate air), B. Sietz filters, C. Berkfield filters, D. Millipore/Porcelain filters', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]