Question

which system works similar to a refrigeration system?
a heat pump
a thermostat
a furnace
a heat engine

Explanation:

A heat pump and a refrigeration system both transfer heat using a refrigerant cycle. A heat pump can reverse the cycle to heat or cool, similar to how a refrigerator (refrigeration system) moves heat from inside (cold space) to outside (warm space). A thermostat is a control device, a furnace generates heat, and a heat engine converts heat to work, so they don't work similarly to a refrigeration system.

Answer:

a heat pump