Which key can be used to temporarily hide all open windows and bring the desktop in focus?

To temporarily hide all open windows and bring the desktop into focus, the Command-M keyboard shortcut is used. This command minimizes the active window, helping to clear the visual clutter on the screen and allowing you to see and access the desktop more easily.

In contrast, while the F3 key is associated with Mission Control, which displays all open windows and spaces, it does not serve to minimize or hide them. The Command-D key is typically used for duplicating items, such as files or images, making it unrelated to focusing on the desktop. The Option-D key does not have a function related to managing windows in this context either. Thus, Command-M is the most appropriate choice for the action described, as it minimizes windows and allows a clear view of the desktop.