What is the keyboard shortcut to undo the last action in AVID Media Composer?

The keyboard shortcut to undo the last action in AVID Media Composer is CTRL + Z. This shortcut is a standard convention across many software applications, not just within the realm of video editing. It allows users to quickly reverse their last action, making it easier to correct mistakes or revert changes without needing to navigate through menus. This functionality is critical for maintaining an efficient workflow, especially during complex editing tasks where numerous changes can be made rapidly.

In AVID Media Composer, using this keyboard shortcut streamlines the editing process, as it does not require the user to take their hands off the keyboard or disrupt their flow by accessing the undo command through the interface. The ability to quickly undo actions is essential in multimedia editing where timelines can be altered frequently.

The other options represent different functions that do not serve the purpose of undoing actions, which is why they are not the correct answer in this context.