From the V$SESSION_LONGOPS view， you find that some of the database users have long­running queries and are consuming a lot of CPU time. This causes problems for you when you try to log on as the system user and perform small maintenance tasks. You would like to ensure that users SYS and SYSTEM get priority over all other users. Which method would you use to achieve this objective？（）

A. create a plan directive in the SYS_GROUP
B. create the pending area for the consumer group
C. activate the provided SYSTEM_PLAN in Resource Manager
D. set the TIMED_STATISTICS parameter to TRUE in the parameter file
E. set the execution time limit for all users， except SYS and SYSTEM， in their profile