What happens to a moist air mass after it rises over a mountain range?

When a moist air mass rises over a mountain range, it cools due to the decrease in atmospheric pressure at higher elevations. As the air cools, it loses its ability to hold moisture, leading to condensation. This process forms clouds and ultimately results in precipitation, such as rain or snow, on the windward side of the mountain. This phenomenon is known as orographic lift, where the terrain forces the humid air to rise, resulting in cooling and the formation of precipitation, which is why the correct answer identifies this process accurately.

In contrast, the other options describe processes that do not accurately reflect what occurs to moist air when it ascends over a mountain range. The air does not warm and generate high-pressure areas; instead, it cools, resulting in precipitation. It also does not absorb moisture from the surrounding air, as the rising air is losing moisture through condensation. Additionally, the air mass does not remain stable and unchanged; it undergoes a significant transformation as it rises, cools, and condenses.