Which statement about using RMAN stored scripts is true？（）  

• A、 To create and execute an RMAN stored script，you must use a recovery catalog.
• B、 When executing a stored script and a command fails，the remainder of the script is executed，and a message is written to the alert log file.
• C、 RMAN stored scripts can always be executed against any target database that is registered in the recovery catalog.
• D、 When you execute a stored script，it always executes using the persistent channel settings previously set with the CONFIGURE command.