The Shy switch is the correct choice for temporarily hiding a layer in the timeline. When a layer is marked with the Shy switch, it will not be displayed in the timeline, which helps to declutter the workspace when working on complex compositions with many layers. This allows you to focus on the layers that are relevant to your current work without permanently deleting or disabling other layers.
The benefit of using the Shy switch is that you can easily toggle the visibility of various layers, maintaining the ability to bring them back into view without losing any settings or effects associated with them. This is particularly useful in large projects where managing multiple layers can become overwhelming.
While other options might sound plausible, they serve different functions. For instance, the Solo switch allows you to isolate a single layer by hiding all other layers, but it does not hide the selected layer temporarily. The Hide option is not a standard term used in After Effects for this purpose, and Deactivate refers to disabling a layer entirely, which is a more permanent action than merely hiding it in the timeline view. Thus, the Shy switch provides the most effective mechanism for temporarily managing layer visibility without affecting other settings or arrangements.