What is commonly found at the leading edge of a cold front?

A cold front is associated with the leading edge of a mass of cooler, denser air that moves into an area occupied by warmer air. As the cold air advances, it forces the warmer air to rise rapidly. This process is crucial because as warm air rises, it cools and can lead to the development of clouds and precipitation. The rapid lifting of the warm air is often accompanied by the formation of cumulonimbus clouds and stormy weather conditions.

The other options do not accurately describe what occurs at the leading edge of a cold front. Stable air typically remains horizontal and does not interact with cold air the same way as warm air does when a cold front moves through. Cool air descending slowly can occur in certain weather conditions, but it does not capture the dynamic activity of a cold front, where the emphasis is on the rapid ascent of warm air. Lastly, a high-pressure zone, which usually indicates stable and clear weather, is not characteristic of the air dynamics at a cold front. Instead, cold fronts typically bring lower pressure systems associated with stormy weather.