In migrating an on-premises Oracle Database using the Cross-Platform Transportable Tablespace feature, the target Database Cloud Service must be at least version 12.1 or later to support this functionality. This is because the Cross-Platform Transportable Tablespace Backup Set feature with the required RMAN clauses is supported starting from Oracle Database 12c. Therefore, the statement that the Database Cloud Service target version must be 12.1 or later is true.