Which method is used to create a new layer from the background layer?

Creating a new layer from the background layer involves converting that background into a regular layer, which can then be manipulated in a more versatile way. When you double-click the background layer in the Layers panel, Photoshop prompts you to rename it and automatically converts it into a standard layer, allowing you to apply layer effects and transformations that are not available to the locked background layer.

This method is particularly useful because it not only creates a new layer by unlocking it but simultaneously gives you the option to rename and organize your layers effectively.

The other methods mentioned, such as duplicating the layer or selecting "New Layer" from the Layer menu, do not specifically result in transforming the background layer into a regular layer; instead, they create additional layers or duplicates, which may not serve the same purpose when starting with a locked background. Therefore, double-clicking the background layer is the most direct and effective method to immediately create a new editable layer from the locked background.