Final answer:
Testing changes on a GPO copy in a test environment helps avoid accidental deployment to production, allowing for safe review and assessment before implementing.
Step-by-step explanation:
By testing changes on a copy of the Group Policy Object (GPO) on test machines, a student would make it much harder to accidentally deploy the changes to production. This is because the changes are being evaluated in a controlled environment where they can be reviewed and tested for functionality and potential issues without affecting the live or production environment. Once the changes are confirmed to be safe and working as intended, they can then be carefully implemented into the production environment.