Study the image, which describes how rapid changes in weather conditions occur.

How rapid changes in weather conditions occur. Arrow labeled Direction of frontal movement points right toward Cold front map symbol. Arrow labeled Rising warm air in front of cold front points from cold front to sky. Also labeled are: Development of clouds because of upward movement of warm air, and Advancing cold air behind cold front.

Based on the arrows, what does the image represent?

Air masses are barely moving.
Air masses are colliding with each other.
Jet streams are forming in the upper atmosphere.
Weather conditions are remaining steady and unchanged.