This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Air, Light, Sound, Housing, Radiation, Waste Disposal, Subject name: Social & Preventive Medicine
[{'content': 'All of the following are types of mechanical ventilation except: \nSelect and explain. \nA. Perflation and aspiration, B. Exhaust ventilation, C. Plenum ventilation, D. Air conditioning', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Perflation and aspiration is a type of Natural Ventilation. Types of ventilation: Natural ventilation: Wind: it blows through a room (perflation) and may exe a suction at its tail end (aspiration). Diffusion: when passes through smallest openings. Inequality of temperature. Mechanical (aificial) ventilation: Exhaust ventilation: air is extracted to outside by exhaust fans driven by electricity. Balanced ventilation: combination of exhaust and plenum ventilation. Air conditioning: simultaneously control of all factors especially temperature, humidity and air movement. Plenum ventilation: fresh air is blown into rooms by centrifugal fans.', 'role': 'assistant'}]