单选题You have created a resource plan， DB_PLAN， using DBMS_RESOURCE_MANAGER.CREATE_SIMPLE_PLAN and you want to impose a restriction on utilization of resources by the database users. Which step must be performed before you can start using the resource plan？
题目
单选题
You have created a resource plan， DB_PLAN， using DBMS_RESOURCE_MANAGER.CREATE_SIMPLE_PLAN and you want to impose a restriction on utilization of resources by the database users. Which step must be performed before you can start using the resource plan？（）
A
assign users to consumer groups
B
set the resource plan for the instance
C
configure a simple resource plan and specify plan directives
D
configure a complex resource plan and specify plan directives
