Which shot is used to reveal something important from the on-screen action?

The correct choice highlights the importance of the insert shot as a cinematic technique. An insert shot focuses on a specific object or detail within the scene, drawing the audience's attention to something important that may not be visible or clear in wider shots. This technique enhances narrative clarity and can provide critical information regarding the plot or character development.

For instance, in a scene where a character discovers a significant item, an insert shot might zoom in on that item, allowing viewers to grasp its importance directly. This method is used effectively to create suspense, build emotion, or clarify intricate plot points without needing a significant change in the overall composition of the scene.

Understanding this, it's clear why the insert shot is singled out; it serves a distinct role in visual storytelling by emphasizing key elements that advance the narrative or deepen the viewer's understanding of the action.