Answer:The correct answer is 'expansion valve'.
Step-by-step explanation:
Function of expansion valve in a refrigerator or in cooling system is to remove the pressure from the liquid refrigerant for the expansion or change in state fro liquid to vapors phase.
The warm refrigerant enters the the valve from one side in which pressure is reduced due to which liquid refrigerant expands and moves out from the other end into the evaporator where it absorbs heat from the air present in that compartment.