The RVPC user can do which of the following？（）

• A、 Register databases if granted the register database privilege
• B、 See all databases in the recovery-catalog schema
• C、 See all database-related metadata in the recovery catalog if they are granted access to that database
• D、 Unregister databases from the RVPC catalog that were not granted to the RVPC catalog owner with  the grant command
• E、 Not be connected to with the RMAN command-line catalog parameter for backup or recovery purposes