Computers on a small network are not able to receive new addresses from the DHCP server.
However, the administrator has checked the server and ensured it is connected, responding, and functional.
Which of the following is the MOST likely problem in this scenario?（）

A. The DHCP server has an incorrect gateway configured.
B. The DHCP server was incorrectly configured with a six hour lease time on addresses.
C. The DHCP server was incorrectly configured with no-expiring lease time on addresses.
D. The DNS server is no longer functional and internal name-address resolution is down.