Your company has a single-domain Active Directory forest. The functional level of the
domain is Windows Server 2008.
You perform the following activities:
Create a global distribution group.
Add users to the global distribution group.
Create a shared folder on a Windows Server 2008 member server.
Place the global distribution group in a domain local group that has access to the shared
folder.
You need to ensure that the users have access to the shared folder.
What should you do?

A.
Add the global distribution group to the Domain Administrators group.

B.
Change the group type of the global distribution group to a security group.

C.
Change the scope of the global distribution group to a Universal distribution group.

D.
Raise the forest functional level to Windows Server 2008.

Explanation:
http://kb.iu.edu/data/ajlt.html
In Microsoft Active Directory, what are security and distribution groups?
In Microsoft Active Directory, when you create a new group, you must select a group type.
The two group types, security and distribution, are described below:
Security: Security groups allow you to manage user and computer access to shared
resources. You can also control who receives group policy settings. This simplifies
administration by allowing you to set permissions once on multiple computers, then to

change the membership of the group as your needs change. The change in group
membership automatically takes effect everywhere. You can also use these groups as email
distribution lists.
Distribution: Distribution groups are intended to be used solely as email distribution lists.
These lists are for use with email applications such as Microsoft Exchange or Outlook. You
can add and remove contacts from the list so that they will or will not receive email sent to
the distribution group. You can’t use distribution groups to assign permissions on any
objects, and you can’t use them to filter group policy settings.
http://technet.microsoft.com/en-us/library/cc781446%28v=ws.10%29.aspx
Group types