View the Exhibit and examine the recommendation graph provided for a test database by the Undo Advisor.The graph recommends that the size of undo tablespace should be set to（）.

A.set DB_FLASHBACK_RETENTION_TARGET=10800  
B.create a new scheduler window for the time period of 24 hours and use the optimizer statistics 
C.modify the Automatic Workload Repository (AWR) snapshot time interval to three hours and use ADDMfindings 
D.specify New Undo Retention as three hours and Analysis Time period as Last One Day in the Undo Advisor page and use its recommendations

A.block level 
B.object level 
C.schema level 
D.segment level 
E.tablespace level

A.add data files to the tablespace 
B.identify the segments that you should shrink 
C.modify the storage parameters for the tablespace 
D.automatically shrink the segments with unused space 
E.check the alerts generated for the tablespace that is running low on space