You observe that the senior database administrator always uses the following command when connecting to Recovery Manager （RMAN）， and then starts executing commands to backup the database files：  $ rman target /  What would be the effect of this command？（）

• A、RMAN would use the current operating system location to place the backup.
• B、RMAN would use the control file of the target database to maintain the backup.
• C、RMAN would use the recovery catalog of the target database to maintain the backup.
• D、RMAN would use the control file of the target database to maintain the backup metadata. 
• E、RMAN would use the recovery catalog of the target database to maintain the backup metadata.