A.Undo data becomes obsolete after 1，000 seconds.
B.Undo data gets refreshed after 1，000 seconds.
C.Undo data will be stored permanently after 1，000 seconds.
D.Committed undo data would be retained for 1，000 seconds if free undo space is available.
E.Undo data will be retained in the UNDOtablespacefor 1，000 seconds， then it gets movedmovedto the TEMPORARYtablespaceto provide read consistency.

A.Until last commit
B.Until the time you perform recovery
C.Until the time the date file got corrupted
D.Until the point where the last transaction begun
E.You cannot recover the SYSTEMtablespaceand must re-create the database.