Which key combination stops speaking in VoiceOver?

In VoiceOver, the correct key combination to stop speaking is the Control (Ctrl) key. When users are using VoiceOver, which is a screen reader feature on macOS, pressing the Control key acts as a universal command to pause or stop speech output. This allows users to easily halt the voice feedback when they need to regain focus or adjust their interaction with the system without disturbing their workflow.

The other keys offered in the options do not serve this function in the context of VoiceOver. The Command (Cmd) key is often utilized for different shortcut commands and functionalities but does not specifically control the speech output of VoiceOver. The Option (Alt) key is used for accessing additional features or for shortcut commands, while the Shift key also modifies operations but does not pertain directly to stopping the speech output in VoiceOver. Thus, the Control key is uniquely designated for this purpose, making it the correct choice.