The Database Resource Manager is automatically enabled in the maintenance window that runs the Automated Maintenance Task. What is the reason for this？（）  

• A、 to prevent the creation of an excessive number of scheduler job classes
• B、 to allow the Automated Maintenance Tasks to use system resources without any restriction
• C、 to allow resource sharing only among the Automated Maintenance Tasks in the maintenance window
• D、 to prevent the Automated Maintenance Tasks from consuming excessive amounts of system resources