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;

A. The ASM-preferred mirror read feature is enabled.
B. The ASM supports variable sizes for extents of 1，8，and 64 allocation units.
C. The ASM disk is dropped immediately from a disk group when it becomes unavailable.
D. The RDBMS always reads the primary copy of a mirrored extent of the ASM disk group.