To comply with the regulation requiring database backups to reside in the same region as the database, and to minimize operational costs and administrative effort, the best approach is to configure the automated backups to use a regional Cloud Storage bucket as a custom location (Option A). This ensures backups are stored in the same region as the database, meeting regulatory requirements, and leverages automated backups to reduce administrative effort. Option B does not guarantee that backups will reside in the same region as the database, as the default configuration might not be region-specific. Options C and D involve disabling automated backups, which increases administrative effort and does not align with the goal of minimizing operational costs and administrative effort.