In a scenario where a Veeam engineer needs to manage backup file transfers between two sites without impacting bandwidth during business hours, the most appropriate feature to configure in the backup copy job is D: Backup Copy Window. The Backup Copy Window setting in Veeam Backup & Replication allows for specifying the time frame during which the backup copy job is allowed to transfer data. By configuring this window to exclude business hours, the engineer can ensure that the backup copy job transfers data only during off-peak hours, thereby avoiding additional strain on the WAN connection when it is most needed for business operations. This approach provides the flexibility to balance the need for offsite backups with the practical bandwidth considerations of a busy WAN connection, ensuring that backup activities do not interfere with critical business functions.