In your production database， you observe that users’ transactions are consuming a lot of resources and you plan to impose resource restrictions by using Resource Manager. For which three resources can you enable usage restrictions by using Resource Manager？ （）
- ACPU usage
- Bdegree of parallelism
- Cnumber of open cursors
- Dnumber of sorts performed
- Eidle time for blocking sessions
- Fnumber of disk I/O operations performed
- Gnumber of memory I/O operations performed