The correct selection is B, C. In Metadata API, the definition of a custom metadata type is represented through CustomObject metadata, while its individual records are CustomMetadata components. Both must be included when moving the complete custom-metadata configuration between environments. From a deployment perspective, the same release should be reproducible across environments, with dependencies, metadata/data differences, API behavior, and target-org constraints identified before production. Automation is valuable because it turns deployment knowledge into a controlled process rather than relying on memory or manual reconstruction. The other choices either rely on manual reconstruction, use a deployment mechanism designed for a different scope, or fail to preserve dependencies and repeatability across target environments. For this scenario, the decisive point is therefore the platform behavior represented by the selected options (B. CustomMetadata; C. CustomObject). Applying that rule consistently keeps the implementation aligned with Salesforce-supported lifecycle practices and makes the resulting change easier to review, validate, and operate across environments.

Study Guide reference: Deploying — Metadata API and Tooling API; deployment validation; package/change-set deployment; data migration; dependency management.