You enable block change tracking. You issue the following command：   BACKUP INCREMENTAL LEVEL 0 DATABASE；   The next day，you issue the following command：   BACKUP INCREMENTAL LEVEL 1 CUMULATIVE DATABASE；   Which statement about the use of the change tracking file is true？（）  

• A、 RMAN reads the block change tracking file only when it performs the incremental level 0 backup.
• B、 RMAN reads the block change tracking file when it performs both incremental backups.
• C、 RMAN reads the block change tracking file only when it performs the incremental level 1 backup.
• D、 RMAN does not read the block change tracking file when it performs either incremental backup.