You are creating a recovery catalog for use with RMAN. You have issued these commands： SQL> CREATE TABLESPACE rman_ts DATAFILE 
’/DISK1/rman_ts01.dbf’ 2> SIZE 20M 3> DEFAULT STORAGE （initial 100K next 100K pctincrease 0）； SQL> CREATE USER rman_db01 IDENTIFIED BY rman_db01 2> DEFAULT TABLESPACE rman_ts 3> QUOTA unlimited ON rman_ts； 
Which command should you issue next？（）

A.data files
B.control files
C.redo log files
D.parameter files
E.archive log files

A.A dispatcher can support multiple client connects concurrently while a shared server process can be dedicated to only one dispatcher. 
B.Under the Oracle Shared Server architecture, client-user processes connect to shared user processes.
C.Each dispatcher has its own request queue, which is monitored every three seconds by the dispatcher. 
D.Oracle Shared Server required Oracle Net Service even if the client and shared server processes reside on the same machine.

A.SMON
B.PMON
C.shared server
D.dedicated server