You work as a database administrator at Certkiller .com. In your production database， you observe that users’ transactions are consuming a lot of resource and you plan to impose resource restrictions by using Resource Manager. For which three resources can you enable usage restrictions by using Resource Manager？ （）

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