You are the network administrator for your company. The company has a main office and a branch office. All client computers run Windows XP Professional. Computers in the main office receive their TCP/IP configuration from DHCP. TCP/IP settings are manually configured on computers in the branch office. The network is configured as shown in the exhibit. Marc is a user who works in the main office. He uses a Windows XP Professional portable computer named Portable1. When he uses Portable1 in the main office, he is able to access resources that are located in both offices. Marc reports that when he visits the branch office and uses Portable1, he is not able to access any network resources that are located in either office. All other users in the branch office are able to access all network resources that are located in both offices. You need to ensure that Marc is able to use Portable1 to access all network resources when he is in either the main office or the branch office. You want to ensure that this goal is accomplished with the minimum amount of administrative effort, with no future administrative action required. What should you do?（）
- AEnable Automatic Private IP Addressing (APIPA) on Portable1.
- BOn Portable1, manually set an alternate TCP/IP configuration for the branch office subnet.
- CConfigure the VPN2 server as a DHCP relay agent.
- DOn Portable1, specify the address of the VPN2 server as an additional gateway address.