Your network contains an Active Directory forest. The forest contains two domains named
contoso.com and woodgrovebank.com.
You have a custom attribute named Attribute 1 in Active Directory. Attribute 1 is associated
to User objects.
You need to ensure that Attribute1 is included in the global catalog.
What should you do?

A.
From the Active Directory Schema snap-in, modify the properties of the Attribute 1
attributeSchema object.

B.
In Active Directory Users and Computers, configure the permissions on the Attribute 1
attribute for User objects.

C.
From the Active Directory Schema snap-in, modify the properties of the User
classSchema object.

D.
In Active Directory Sites and Services, configure the Global Catalog settings for all
domain controllers in the forest.

Explanation:
http://technet.microsoft.com/en-us/library/how-global-catalog-servers-work.aspx
Global Catalog Partial Attribute Set
The attributes that are replicated to the global catalog by default include a base set that have
been defined by
Microsoft as the attributes that are most likely to be used in searches. Administrators can
use the Microsoft Management Console (MMC) Active Directory Schema snap-in to specify
additional attributes to meet the needs of their installation. In the Active Directory Schema
snap-in, you can select the Replicate this attribute to the global catalog check box to
designate an attributeSchema object as a member of the PAS, which sets the value of the
isMemberOfPartialAttributeSet attribute to TRUE.
Global Catalog Replication of Additions to the Partial Attribute Set Each global catalog
server in an AD DS forest hosts a copy of every existing object in that forest. For the objects
of its own domain, a global catalog server has information related to all attributes that are
associated with those objects. For the objects in domains other than its own, a global catalog
server has only information that is related to the set of attributes that are marked in the AD
DS schema to be included in the partial attribute set (PAS). As described earlier, the PAS is
defined by Microsoft as those attributes that are most likely to be used for searches. These
attributes are replicated to every global catalog server in an AD DS forest.
If you want to add an attribute to the PAS, you can mark the attribute by using the Active
Directory Schema snap-in to edit the isMemberOfPartialAttributeSet value on the respective
attributeSchema object. You mark the attribute by placing a checkmark next to
isMemberOfPartialAttributeSet. If the
isMemberOfPartialAttributeSet value is checked (set to TRUE), the attribute is replicated to
the global catalog.
If the value is not checked (set to FALSE), the attribute is not replicated to the global catalog.