单选题You are using Oracle Database 10g. The LOG_ARCHIVE_FORMAT parameter is set to  ’LOG%t_%s_%r.dbf’.  Why is %r used in the file name format？（）A to uniquely identify the archived log files with the restore operationB to uniquely identify the archived log 

to uniquely identify the archived log files with the restore operation

to uniquely identify the archived log files with the redo log group number

to uniquely identify the archived log files for each incarnation of the database

to uniquely identify the archived log files with the number of recovery operations performed