The correct answer is A. Expansion.
Rising air cools by expansion. As air rises, it expands and cools. This is because the pressure of the air decreases as it rises. The lower pressure allows the air molecules to spread out more, which makes them move slower and have less energy. This lower energy causes the air to cool.
Option B, evaporation, is the process by which a liquid changes into a gas or vapor. This happens when the molecules in the liquid have enough energy to escape from the surface of the liquid and enter the air. Evaporation does not cause air to cool.
Option C, compression, is the process by which a gas or vapor is forced into a smaller space. This causes the molecules in the gas or vapor to move closer together, which makes them move faster and have more energy. This higher energy causes the gas or vapor to heat up.
Option D, condensation, is the process by which a gas or vapor changes into a liquid. This happens when the molecules in the gas or vapor lose energy and slow down. Condensation does not cause air to cool.