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
Psychrometer is used to measure 
Select and explain. 
A. Humidity, B. Air velocity, C. Room temperature, D. Radiant heat
A: Humidity
Answer: A: Humidity 
Explanation: • Air humidity can be measured by:
Dry and wet bulb thermometers
Hygrometer
Sling/Whirling Psychrometer
Assman Psychrometer