Which statement is true about the UNDO_RETENTION parameter when retention guarantee is notenabled（）

A、It is the time period after which the undo data becomes obsolete.

B、It is the time period after which the committed undo data would be transferred to a temporarytablespace.

C、It is the minimum time period up to which the committed undo data would be retained if free undo spaceis available.

D、It is the time period after which the undo data is transferred to the Flash Recovery Area to provide readconsistency.