You are managing an Oracle Database 11g database with the following backup strategy：  1.On Sunday， an incremental level 0 tape backup is performed.  2.Monday through Saturday， acumulativeincremental level 1 tape backup is performed.  Which two statements are true regarding the backups performed（）

• A、The backup performed in step 1 backs up all blocks that have ever been in use in the database. 
• B、The backup performed in step 2 copies all the blocks changed since the most recent level 0 backup.
• C、The backup performed in step 1 backs up all the blocks changed since the most recent level 1 backup.
• D、The backup performed in step 2 backs up all blocks that have changed since the most recent incremental backup at level 1.