Concept:An air conditioner controls both temperature and humidity for indoor comfort.Explanation:A compressor only increases the pressure of a gas. It does not control room conditions directly.A refrigerator cools a small enclosed space but does not manage the humidity or temperature of a building.An air blower simply moves air around without adjusting temperature or humidity.An air conditioner removes heat and excess moisture from the air. It maintains the correct temperature and humidity in an occupied space.Answer:D. Air conditioner