OCP CBT Question 578

Please solve the following question.

Examine the following scenario:```sqlSHOW PARAMETER UNDO_TABLESPACE;``````NAME TYPE VALUE-------------------- ----------- ------------------------------undo_tablespace string UNDOTBS1```You want to switch the current undo tablespace from `UNDOTBS1` to a newly created undo tablespace named `UNDOTBS2`. Which set of commands would correctly achieve this?

ALTER SYSTEM SET UNDO_TABLESPACE = 'UNDOTBS2';DROP TABLESPACE UNDOTBS1;

ALTER DATABASE SET UNDO_TABLESPACE = UNDOTBS2;

ALTER SYSTEM SET UNDO_TABLESPACE = UNDOTBS2 SCOPE=SPFILE;SHUTDOWN IMMEDIATE;STARTUP;ALTER TABLESPACE UNDOTBS1 OFFLINE;

ALTER SYSTEM SET UNDO_TABLESPACE = 'UNDOTBS2';