问题：

[单选]

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 . Raise the forest functional level to Windows Server 2008.
B . Add the global distribution group to the Domain Administrators group.
C . Change the group type of the global distribution group to a security group.
D . Change the scope of the global distribution group to a Universal distribution group.