Yournetwork contains two Active Directory forests named contoso.com and adatum.com.
Contoso.com contains one domain. Adatum.com contains a child domain named child.adatum.com.
Contoso.com has a one-way forest trust to adatum.com. Selective authentication is enabled on the
forest trust.
Several user accounts are migrated from child.adatum.com to adatum.com.
Users report that after the migration, they fail to access resources in contoso.com. The users
successfully accessed the resources in contoso.com before the accounts were migrated.
You need to ensure that the migrated users can access the resources in contoso.com.
What should you do?

A.
Replace the existing forest trust with an external trust.

B.
Run netdom and specify the /quarantine attribute.

C.
Disable SID filtering on the existing forest trust.

D.
Disable selective authentication on the existing forest trust.

Explanation:
Security Considerations for Trusts
Need to gain access to the resources in contoso.com
Disabling SID Filter Quarantining on External Trusts
Although it reduces the security of your forest (and is therefore not recommended), you can disable
SID filter quarantining for an external trust by using the Netdom.exe tool. Youshould consider
disabling SID filter quarantining only in the following situations:
* Users have been migrated to the trusted domain with their SID histories preserved, and you want
to grant them access to resources in the trusting domain based on the SID history attribute.
Etc.
Incorrect:
Not B. Enables administrators to manage Active Directory domains and trust relationships from the
command prompt, /quarantine Sets or clears the domain quarantine.
Not D. Selective authentication over a forest trust restricts access to only those users in a trusted
forest who have been explicitly given authentication permissions to computer objects (resource
computers) that reside in the trusting forest.
Security Considerations for Trusts
http://technet.microsoft.com/en-us/library/cc755321(v=ws.10).aspx