Your network consists of a single Active Directory domain. All servers run Windows Server 2003 Service Pack 2 (SP2). All client computers run Windows XP Professional Service Pack 3 (SP3). You enable and configure Terminal Server on a server named Server1. A firewall separates Server1 from the internal network. Internal users report that they cannot connect to Server1 by using Remote Desktop Connection. You need to ensure that the users can connect to Server1 by using Remote Desktop Connection. Which port should you open on the firewall? （）

• A、389
• B、3268
• C、3389
• D、5900