Your network contains 100 client computers that run Windows 7.
Five of the client computers are members of a workgroup.
The network contains an enterprise root certification authority (CA).
You deploy a Lync Server 2010 Standard Edition server named Server1 that uses a Web Server certificate from the CA.
You install Microsoft Lync 2010 on all client computers.
You need to ensure that all client computers can sign in to Server1 by using Lync 2010.
What should you do on the workgroup client computers?

A.
Run certreq.exe -enroll.

B.
Run certutil.exe -isvalid.

C.
Import the Web Server certificate of Server1 to the Trusted Publishers store.

D.
Import the root CA certificate to the Trusted Root Certification Authorities store.