A.when the data file of the undo tablespace is autoextensible
B.when there are more than one undo tablespaces available in the database
C.when the undo tablespace is of a fixed size and retention guarantee is not enabled
D.when the undo tablespace is autoextensible and retention guarantee is not enabled

A.The extents in the undo tablespace retain data until the next full database backup.
B.The extents containing committed undo in the undo tablespace are not overwritten for at least 15minutes.
C.The extents containing committed data in the undo tablespace are not overwritten until the instance isshut down.
D.The extents containing committed undo in the undo tablespace are transferred to Flash Recovery Areabefore being overwritten.