You need to configure AD FS to ensure that AD FS tokens contain information from the Active Directory domain
You need to ensure that users at the branch office are able to log on to the domain by using the RODC
You need to configure the intranet.adatum.com zone to allow only domain members to dynamically register DNS records
You need to ensure that the Contoso users are able to resolve names from the intranet.fabrikam.com domain