问题：

[单选] Your company uses DHCP to lease IPv4 addresses to computers at the main office. A WAN link connects the main office to a branch office. All computers in the branch office are configured with static IP addresses. The branch office does not use DHCP and uses a different subnet.  You need to ensure that the portable computers can connect to network resources at the main office and the branch office.How should you configure each portable computer（）？

A . Use a static IPv4 address in the range used at the branch office.
B . Use an alternate configuration that contains a static IP address in the range used at the main office.
C . Use the address that was assigned by the DHCP server as a static IP address.
D . Use an alternate configuration that contains a static IP address in the range used at the branch office.