What media storage selection defines media as external in Final Cut Pro?

The selection that defines media as external in Final Cut Pro is to "Leave files in place." When you choose this option, you are indicating that the media files will remain in their original locations on external drives or directories rather than being imported into the Final Cut Pro library. This option is beneficial for maintaining an organized workflow when working with large projects, as it ensures you don’t duplicate files unnecessarily within the library, which can lead to increased storage usage and potential confusion over file management.

In contrast, the other options would actually either move the files into the Final Cut Pro library or copy them there, thus making them part of the library’s internal structure rather than leaving them as external files. This allows for different workflows depending on the needs of the project and the storage capabilities available.