Stored Object Encryption is the StorageGRID encryption method that is available regardless of how the grid nodes are deployed. It is configured centrally in Grid Manager rather than depending on appliance-specific hardware capabilities. When enabled, StorageGRID encrypts newly ingested S3 object data that has not already been encrypted at the bucket or object level. StorageGRID supports AES-128 or AES-256 for this function.
The other options are deployment-specific. Node Encryption is associated with StorageGRID appliance nodes and a configured external Key Management Server (KMS); it must be enabled for an eligible appliance during installation. Drive Security depends on storage appliances equipped with Full Disk Encryption or self- encrypting drives and is managed through SANtricity System Manager. Drive Encryption likewise requires StorageGRID appliances containing supported self-encrypting drives and is configured through the StorageGRID Appliance Installer. These hardware dependencies mean none of those three methods is universally available across virtual, containerized, cloud, and appliance deployment models.
Therefore, C. Stored Object Encryption is the correct answer because it operates at the StorageGRID object- ingest layer rather than relying on a particular node or disk hardware implementation.
Reference topics: Grid Manager # Security Settings # Network and Objects # Stored Object Encryption; StorageGRID Encryption Methods