Your network contains an Active Directory domain named contoso.com. The domain contains a
server named Server1 that runs Windows Server 2012 R2. Server1 has the Active Directory Rights
Management Services server role installed.
Your company works with a partner organization that does not have its own Active Directory Rights
Management Services (AD RMS) implementation.
You need to create a trust policy for the partner organization.
The solution must meet the following requirements:
Grant users in the partner organization access to protected content.
Provide users in the partner organization with the ability to create protected content.
Which type of trust policy should you create?

A.
A federated trust

B.
Windows Live ID

C.
A trusted publishing domain

D.
A trusted user domain

Explanation:
In AD RMS rights can be assigned to users who have a federated trust with Active Directory
Federation Services (AD FS). This enables an organization to share access to rights-protected content
with another organization without having to establish a separate Active Directory trust or Active
Directory Rights Management Services (AD RMS) infrastructure.
Incorrect:
Not C. Trusted publishing domains allow one AD RMS server to issue use licenses that correspond
with a publishing license issued by another AD RMS server, but in this scenario the partner
organization does not have any Active Directory.
Not D. A trusted user domain, often referred as a TUD, is a trust between AD RMS clusters, but in
this scenario the partner organization does not have any Active Directory.

AD RMS and AD FS Considerations
http://technet.microsoft.com/en-us/library/dd772651(v=WS.10).aspx