Your network consists of a single Active Directory domain and a single subnet. The network is not connected to the Internet. All servers run Windows Server 2003 Service Pack 2 (SP2). All client computers run Windows XP Professional Service Pack 3 (SP3). You have a DHCP server named Server1. All client computers receive their IP configurations from Server1. You implement a new server named Server2. You connect Server2 to the internal network and the Internet. You then configure Server2 as a network address translation (NAT) router. From a client computer, you discover that you cannot access any Internet servers. From Server2, you verify that you can access Internet servers and internal servers. You need to ensure that all internal computers can access Internet servers.  What should you do?（）  

• A、On Server2, add a new route.  
• B、On Server1, create a multicast scope.  
• C、On Server1, add the Router scope option.  
• D、On Server2, modify the default gateway address.