In a refrigerator, what produce the cooling?

Refrigerators work by using a special substance that changes easily between liquid and gas.

Option A is incorrect because the ice in the freezer is a *result* of the cooling, not the *cause*.

Option B is the correct answer. The refrigerator uses a compressor to squeeze a gas, making it very hot. This hot gas then passes through coils (usually on the back of the fridge) where it releases its heat into the surrounding air. After that, the gas expands suddenly, and this expansion makes it much colder. This cold gas then absorbs heat from the inside of the refrigerator, cooling it down.

Option C is partially correct. While the *evaporation* of a liquid does cool things down, in a refrigerator, the cooling is mainly due to the sudden expansion of the compressed gas. The evaporation plays a supporting role in the cycle.

Option D is incorrect because the correct answer is Option B.