You execute the following command to create two consumer groups， FIN_GROUP1 and PAY_GROUP1， for a plan，PROD_PLAN： 
BEGIN 
DBMS_RESOURCE_MANAGER.CREATE_SIMPLE_PLAN （SIMPLE_PLAN => ’prod_plan’， 
CONSUMER_GROUP1 => ’fin_group1’， 
GROUP1_CPU => 80， 
CONSUMER_GROUP2 => ’pay_group1’， 
GROUP2_CPU => 20）; 
END; 
Which three statements are true？（）

A.The Resource Manager plan does not affect the user.
B.There must be a plan directive in any of the plans of the group to control the resources.
C.The members of the group DEFAULT_CONSUMER_GROUP always have resource restrictions.
D.The members of DEFAULT_CONSUMER_GROUP are restrained from accessing the system tables.
E.The members of this group can change their group without the database administrator’s intervention.

A.The members of LOW_GROUP would get more priority than those of OTHER_GROUPS.
B.The members of SYS_GROUP would get most of the CPU allocation at level 1.
C.The members of LOW_GROUP would get most of the CPU allocation because it has CPU allocation at two different levels.
D.The members of LOW_GROUP would get no CPU allocation at level 1 if the members of OTHER_GROUPS are using all the CPU at level 2.
E.The members of SYS_GROUP would get no CPU allocation at level 1 if the members of OTHER_GROUPS are using all the CPU at level 2.

A.CPU usage
B.degree of parallelism
C.number of open cursors
D.number of sorts performed
E.idle time for blocking sessions
F.number of disk I/O operations performed
G.number of memory I/O operations performed