Which environmental conditions must be controlled under the AWA?

The choice that identifies the correct environmental conditions that must be controlled under the Animal Welfare Act (AWA) is centered on the comprehensive requirements for maintaining a suitable environment for animals. The AWA mandates that facilities ensure adequate temperature, humidity, and air quality in animal housing to promote the well-being of the animals.

Temperature and humidity control are essential for ensuring that animals are kept within ranges that support their health and comfort. Extreme temperatures or humidity levels can lead to stress or health issues for the animals. Additionally, air quality is critical since contaminants or inadequate ventilation can affect animals' respiratory health and overall quality of life. Thus, the combination of temperature, humidity, and air quality encompasses all necessary aspects for the ethical treatment of animals in research or commercial settings, aligning with the AWA’s focus on providing a humane environment.

This thorough approach is why the option mentioning all three elements—temperature, humidity, and air quality—accurately reflects the intent and requirements of the AWA regarding environmental conditions.