Which of the following statements best describes Flashback Versions Query？（）  

• A、 Flashback Versions Query is used to make changes to multiple versions of data that existed between two points in time.
• B、 Flashback Versions Query is used to view all version changes on rows that existed between the time  the query was executed and a point in time in the past.
• C、 Flashback Versions Query is used to view version changes and the SQL to undo those changes on rows that existed between two points in time.
• D、 Flashback Versions Query is used to view all version changes on rows that existed between two  points in time.