Archive file format LOG_ARCHIVE_FORMAT is defined as arch_%s.arc. A week ago， you just archived arch_4.arch to tape， then removed all archived files to save disk space. Yesterday you saw arch_10.arc and arch_11.arc on the disk. Today， you see arch_3.arc in the archive directory.  Which two could you happened？（）

• A、Redo logs were restored from tape for recovery. 
• B、The file names are only used when they are copied to tape. 
• C、The database was opened with the RESETLOGS option and log numbers restarted. 
• D、Log names run in circular fashion; arch_3.arc is re-created by the ARCn process. 
• E、A file name is randomly chosen by the archive process; as long as it is unique, it does not have to be sequential.