669.User SCOTT wants to back out the transactions on the REGIONS

669.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? (Choose four.)

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;

正确答案是BCDF