An organization runs an encrypted Amazon RDS for Oracle instance and needs its backups to be routinely available in a different AWS Region. Which approach is the MOST operationally efficient and satisfies this requirement?

Modifying the DB instance to enable cross-Region automated backups is the most operationally efficient solution. This feature directly addresses the requirement for routine backups in a different AWS Region by automating the process, including encryption and retention policies, with minimal manual intervention. Launching a read replica and then taking snapshots is less efficient because it introduces an extra layer of management for the read replica and its snapshots, which is not as streamlined as the built-in automated backup feature. Using AWS DMS is designed for ongoing data replication or one-time migrations, not primarily for routine disaster recovery backups of an entire RDS instance, making it overly complex for this specific backup requirement. Temporarily disabling encryption is not a viable or secure option as it compromises data security and is generally not supported for encrypted RDS instances.