You are managing an Oracle Database 10g database that uses Oracle Managed Files （OMF）. You enabled the block change tracking feature for the database. Which statement regarding the change tracking file is true？（）

• A、 One block change tracking file is created for each data file. By default， the file is created in DB_CREATE_FILE_DEST.
• B、 One block change tracking file is created for each data file. By default， the file is created in BACKGROUND_DUMP_DEST.
• C、 One block change tracking file is created for the database. By default， the file is created in DB_CREATE_FILE_DEST.
• D、 One block change tracking file is created for the database. By default， the file is created in BACKGROUND_DUMP_DEST.