Question

describing refrigeration systems
which statement describes refrigeration systems?
refrigeration systems add cold air to the inside of a building.
refrigeration systems remove all thermal energy from inside the building.
refrigeration systems keep thermal energy from being exhausted from the building.
refrigeration systems move the thermal energy from the building to another place.

Explanation:

Refrigeration systems work based on the principle of heat transfer. They do not add cold air (cold is just the absence of heat in a relative sense). Removing all thermal energy is impossible as per the laws of thermodynamics. They also do not keep thermal energy from being exhausted. Instead, they use a cycle (like the vapor - compression cycle) where a refrigerant absorbs heat (thermal energy) from the inside of the building (or the cold reservoir) and releases it to another place (the hot reservoir).

Answer:

Refrigeration systems move the thermal energy from the building to another place.