You are trying to determine how many disk sorts are happening on the database right now. Which of the following dictionary tables would you use to find that information?（）

A.DBA_TABLESPACES 
B.DBA_TABLES 
C.DBA_SEGMENTS 
D.DBA_FREE_SPACE

A.Redo log switches. 
B.UPDATE statements are issued against the database. 
C.The SYSTEM tablespace is accessed. 
D.SMON coalesces free space in a tablespase.

A.V$CONTROLFILE 
B.V$DATABASE 
C.init.ora 
D.DBA FILES