You work as a database administrator for Certkiller .com. According to your backup strategy， you performed an incremental level 0 backup of your database. Which statement regarding this backup is true？（）

• A、The backup is similar to image copy.
• B、The backup contains all used data blocks.
• C、The backup contains only unused data blocks.
• D、The backup contains all data blocks changed since the last incremental level 1 backup.