Answer:
Clausius statement of the Second Law of Thermodynamics.
Explanation:
The fact that refrigerator requires energy to move the heat from a colder reservoir to a hotter reservoir is a real life observation of the Clausius statement of the Second Law of Thermodynamics.
Clausius statement tells that it is impossible to construct a device operating in a cycle that transfer heat from a low temperature reservoir to a higher temperature reservoir without consuming any work.
