Which statement is true about the UNDO_RETENTION parameter when retention guarantee is notenabled（）
- AIt is the time period after which the undo data becomes obsolete.
- BIt is the time period after which the committed undo data would be transferred to a temporarytablespace.
- CIt is the minimum time period up to which the committed undo data would be retained if free undo spaceis available.
- DIt is the time period after which the undo data is transferred to the Flash Recovery Area to provide readconsistency.