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: Social & Preventive Medicine
[{'content': 'Psychrometer is used to measure \nSelect and explain. \nA. Humidity, B. Air velocity, C. Room temperature, D. Radiant heat', 'role': 'user'}, {'content': 'Answer: A \nExplanation: • Air humidity can be measured by:\nDry and wet bulb thermometers\nHygrometer\nSling/Whirling Psychrometer\nAssman Psychrometer', 'role': 'assistant'}]