User SCOTT wants to back out the transactions on the REGIONS table in his schema. As a DBA, which commands must you execute to enable SCOTT to flash back the transactions?（）

• A、ALTER DATABASE FLASHBACK ON;
• B、GRANT SELECT any transaction TO scott;
• C、GRANT EXECUTE ON dbms_flashback TO scott;
• D、ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;
• E、ALTER TABLESPACE undots1 RETENTION GUARANTEE;
• F、ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (PRIMARY KEY) COLUMNS;