After selecting the audio file, what button do you press to complete the insert?

The button that completes the insertion of an audio file after selecting it is the one labeled 'Insert.' When you select an audio file to add to your PowerPoint presentation, this button activates the process of embedding the selected audio into the current slide. By pressing 'Insert,' you're confirming your choice and initiating the action to include that audio file in your presentation.

Inserting multimedia elements, such as audio, enhances the engagement level of your slides. The other buttons listed serve different purposes; for example, 'Close' would typically exit a dialog box without making changes, 'OK' is often used in context where a confirmation is needed but isn’t specifically used for inserting an audio file in this scenario, and 'Apply' might be relevant in settings for applying changes but does not complete the insert action for audio. Understanding these functions helps ensure proper multimedia integration within your presentations.