You have a production instance running on your server. UNDO_RETENTION is not long
enough to satisfy read-consistency requirements. How do you change the
UNDO_RETENTION value?
A.
by executing UPDATE.. statement on V$PARAMETER to change the value of
UNDO_RETENTION
B.
by executing the ALTER SYSTEM .. command
C.
by re-creating the control file with a new value for UNDO_RETENTION
D.
by executing the ALTER DATABASE.. command in the MOUNT state
B