Your network includes the servers shown in the following table. Server n ame Operating s ystem Role s ervices S erver 1 Windows Server 2008 R2 Standard RDS Licensing S erver 2 Windows Server 2008 R2 Enterprise Remote Desktop Server3 Windows Server 2008 R2 Enterprise Remote Desktop Per-device Remote Desktop Services client access licenses （RDS CALs） are installed on Server1. After you refresh a group of client computers with Windows 7， users on those computers can no longer connect to Server2. You need to ensure that the users can connect to remote applications. What should you do？（）

A. From the affected client computers， initiate a Remote Desktop connection to Server1.
B. From the affected client computers， initiate a Remote Desktop connection to Server3.
C. On the affected client computers， open port 3389 on the Windows Firewall.
D. On Server1， revoke the RDS device CALs of the affected client computers.