A client has a laptop screen and an external screen. Which of the following is the BEST way to toggle between the two or show both at the same time?

Most laptops have a function key (e.g., Fn+F4, Fn+F7, or Fn+F8 depending on manufacturer) mapped to cycle through display modes: laptop only, external only, duplicate (mirror), and extended. This is the fastest and most direct method because it is a single hardware-level keyboard shortcut that does not require opening any application or settings panel.

Task Manager is a system monitoring and process management tool and has no functionality for controlling display output or monitor configuration.

Display Settings in Control Panel can configure monitors but requires navigating through multiple menus, making it slower and less efficient than a single key combination.

Physically powering monitors on and off does not switch the video output signal from the GPU and does not control which display is active from the operating system's perspective.