Which two are prerequisites for performing a flashback transaction?

Which two are prerequisites for performing a flashback transaction?

A.
Flashback Database must be enabled.

B.
Undo retention guarantee for the database must be configured.

C.
EXECUTE privilege on the DBMS_FLASHBACK package must be granted to the user flashing
back transaction.

D.
Supplemental logging must be enabled.

E.
Recycle bin must be enabled for the database.

F.
Block change tracking must be enabled tor the database.

Explanation:
B: Specify the RETENTION GUARANTEE clause for the undo tablespace to ensure
that unexpired undo data is not discarded.
C: You must have the EXECUTE privilege on the DBMS_FLASHBACK package.
Note:
* Use Flashback Transaction to roll back a transaction and its dependent transactions while the
database remains online. This recovery operation uses undo data to create and run the
corresponding compensating transactions that return the affected data to its original state.
(Flashback Transaction is part of DBMS_FLASHBACK package.)
Reference: Oracle Database Advanced Application Developer’s Guide 11g, Using Oracle
Flashback Technology