Your network consists of a single Active Directory domain. The functional level of the domain is Windows Server 2008 R2.
All domain controllers run Windows Server 2008 R2. A corporate policy requires that the users from the research department have higher levels of account and password security than other users in the domain.
You need to recommend a solution that meets the requirements of the corporate policy. Your solution must minimize hardware and software costs.

What should you recommend?

A.
Create a new Active Directory site. Deploy a Group Policy object (GPO) to the site.

B.
Create a new Password Settings Object (PSO) for the research department’s users.

C.
Create a new organizational unit (OU) named Research in the existing domain. Deploy a Group Policy object (GPO) to the Research OU.

D.
Create a new domain in the forest. Add the research department’s user accounts to the new domain. Configure a new security policy in the new domain.

Explanation:
http://technet.microsoft.com/en-us/library/cc770842%28WS.10%29.aspx
http://technet.microsoft.com/en-us/library/cc754461%28WS.10%29.aspx