Enable cross-Region automated backups on a Multi-AZ RDS for PostgreSQL deployment and Create a cross-Region Read Replica and plan to promote it during a Regional outage are the correct choices because they provide cross-Region recoverability and a warm standby that can be used if an entire AWS Region fails.

Enable cross-Region automated backups on a Multi-AZ RDS for PostgreSQL deployment lets you have automated backups copied to a different Region so you can perform point in time recovery outside the affected Region. This approach preserves recoverable snapshots and logs and lets you restore the database in another Region with minimal data loss.

Create a cross-Region Read Replica and plan to promote it during a Regional outage provides a read scale target that lives in another Region and can be promoted to a primary if the home Region becomes unavailable. Promoting the replica gives you a warm standby and faster recovery of service compared to rebuilding from backup alone.

Switch the RDS instance to Provisioned IOPS (SSD) storage instead of General Purpose storage improves disk performance and IOPS consistency but it does not replicate data to another Region and so it does not deliver regional disaster recovery.

Rely only on RDS Multi-AZ with automated backups retained in the same Region provides strong in-Region availability and failover to a standby within the same Region but it does not protect against a full Region outage so it does not meet a regional disaster recovery requirement.

Migrate the database to Amazon Aurora Global Database would offer cross-Region capabilities but it requires moving to the Aurora engine which is a migration task and out of scope for an RDS for PostgreSQL instance in this scenario. This makes it an impractical choice for the given constraint.

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