What type of file in Adobe Photoshop preserves layers?

The correct choice is a Photoshop Document (PSD) because it is the native file format for Adobe Photoshop. When a file is saved as a PSD, it preserves all the layers, adjustments, and effects that are applied to the graphics within the document. This allows for further editing and manipulation of each individual layer at any time, which is essential for complex designs that require ongoing adjustments.

In contrast, JPG and GIF formats are raster image formats that flatten the image into a single layer when saved, thus losing all the layer information. While PNG can support transparency and is often used for web images, it also does not retain layers once saved in that format. Therefore, a PSD file is the ideal choice for graphic designers who need to maintain their layer structure for future editing.