The current time is 12：00 noon. You want to recover the USERS tablespace from a failure that occurred at 11：50 a.m. You discover that the only member of an unarchived redo log group containing information from 11：40 a.m. onwards is corrupt. With reference to this scenario， if you are not using Recovery Manager （RMAN）， which recovery method would you use？（）
- Atimebased recovery
- Blog sequence recovery
- Ccancelbased recovery
- Dchangebased recovery