You have many users complaining about slow inserts into a large table. While investigating the reason， you find that the number of indexes on the table is high. You want to find out which indexes are not being used.  Which method would you follow to achieve this？（） 

• A、enable index monitoring and query the DBA_OBJECTS view
• B、enable index monitoring and query the DBA_INDEXES view
• C、enable index monitoring and query the V$OBJECT_USAGE view
• D、enable index monitoring and view the DBA_INDEXTYPE_COMMENTS view