In which situation is the UNDO_RETENTION parameter be ignored, even if it is set to a value()
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