Your Oracle Database 10g is online when you execute the following statement：        SQL>ALTER TABLESPACE MY_TABLESPACE FLASHBACK OFF；   What is the result of executing this statement if the Flashback Database feature is already enabled in the database？（）

• A、 The database does not record flashback logs for MY_TABLESPACE
• B、 The tables residing in MY_TABLESPACE are not protected by the Recycle Bin.
• C、 All the tablespaces except MY_TABLESPACE can be recovered using Flashback Database feature.
• D、 None of the flashback technologies， such as Flashback Table， Flashback Transaction Query and Flashback Version Query can be used to recover individual rows within the objects from MY_TABLESPACE