What is the key feature of a cold front?

A cold front is defined by its rapid movement and the significant changes it brings to the weather conditions in its wake. The key feature of a cold front is that it moves quickly, often resulting in a sharp drop in temperature as it pushes warmer air upward. This rapid displacement of warm air can lead to the formation of cumulus or cumulonimbus clouds, which are frequently associated with thunderstorms. This transition occurs due to the denser cold air displacing the lighter warm air, causing instability in the atmosphere.

The meteorological impacts of a cold front often include heavy precipitation, strong winds, and a noticeable change in weather patterns, particularly as the front passes. Thus, option B encapsulates these characteristics by highlighting the quick movement, association with thunderstorms, and the sharp temperature drop that accompanies the front. This understanding is essential for predicting weather changes and safety during severe weather conditions.