Which statement would you make about sharing I/O resources in an Exadata environment?

Which statement would you make about sharing I/O resources in an Exadata environment?

A.
You can manage workloads within a database with Database Resource Manager.

B.
You can manage workloads across multiple databases with Database Resource Manager.

C.
You can manage workloads within a database with I/O Resource Manager.

D.
You cannot manage workloads across multiple databases.

Explanation:
http://www.slideshare.net/mrabne/exadata-v2-for-oltp-and-dwh-2236244
slide 60