What keyboard shortcut reveals the keyframes for the selected layer?

The keyboard shortcut that reveals the keyframes for the selected layer is indeed the letter U. When you press U, After Effects quickly displays all the properties of the selected layer that have keyframes assigned to them. This is particularly useful for animators and compositors, as it allows them to rapidly access the keyframes for adjustments and fine-tuning.

In contrast to other options, none of the alternative shortcuts result in the display of keyframes. For example, Shift + K does not have a specific function related to keyframes; it may serve other navigation or control purposes. Similarly, Ctrl + K opens the Composition Settings dialog, which is unrelated to keyframes and layer properties. Finally, Alt + K does not have an assigned action that involves keyframe manipulation or visibility. Therefore, utilizing the U key is the most efficient method for revealing keyframes, enabling a smoother workflow for animating and editing layers in After Effects.