Which statement is correct about enterprise Management Ops Center?

Which statement is correct about enterprise Management Ops Center?

A.
To monitor Exalogic’s hardware components, you must install Enterprise Manager Ops Center
on one of the Exalogic compute nodes.

B.
To monitor Exalogic’s hardware components, you must install enterprise Manager Ops Center
on all Exalogic compute nodes.

C.
To monitor Exalogic’s hardware components, you must install Enterprise Manager Ops Center
on Exalogic storage appliance.

D.
You can install Enterprise Manager Ops Center outside of Exalogic.

Explanation:
http://docs.oracle.com/cd/E18476_01/doc.220/e18478/manage.htm (Prerequisites)