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