问题：

[单选]

You are the network administrator for your company.You work in the company’s branch office in Chicago. The network in your office consists of 40 Windows XP Professional desktop computers and one Windows Server 2003 computer named Server1. Server1 connects to the Internet through a 512-Kbps leased line. The main office of the company is in Seattle.Users of the desktop computers in the Chicago office are developers who are developing a new software product. You want these users to place daily builds of the product in a shared folder on Server1. You want developers in the Seattle office to be able to download the daily builds from Server1 by using FTP.You install IIS on Server1 and configure the FTP site so that it is available to the developers in the Seattle office. However， when you monitor inbound Internet connection attempts to Server1， you notice many attempted HTTP connections.You want to secure Server1 so that it is not susceptible to malicious Internet users. Server1 must also connect to the Internet to use Windows Update and to download virus definition updates. You do not want to purchase additional hardware or software.  
What should you do on Server1？（）

A . Enable Internet Connection Sharing （ICS）.
B . Configure port filtering on the network adapter to allow only TCP port 80 and TCP port 21.
C . Enable Internet Connection Firewall （ICF） and create a service setting in the Internet Connection Firewall settings that allows Internal and external TCP port 21 to Server1  internal and external TCP port 80 to Server1
D . Enable Internet Connection Firewall （ICF） and select the FTP Server check box in the Services tab. Enter Server1 as the server hosting the FTP services.