An administrator is validating disaster recovery mechanisms and wants to ensure backup data is usable and accurate. Which of the following should the administrator do?

Backup verification checks that the backup data written to media is complete and uncorrupted, while testing restorability confirms that files can actually be read back and recovered in a disaster scenario. Together these steps prove that the disaster recovery mechanism works end-to-end, which is precisely what the administrator needs to validate. No other option directly tests whether the backup data can actually be used to recover systems.

Labeling media improves organization and reduces the risk of using the wrong tape but does not verify the integrity or accuracy of the backup data itself.

Storing backups in a secure location is a good security and DR practice but does not confirm whether the backup data is usable or accurate.

Keeping all backups onsite close to the server is actually contrary to disaster recovery best practices because a site-level disaster such as fire or flood would destroy both the server and its backups simultaneously.