You manage a local area network with several switches. A new employee has started today, so you connect her workstation to a switch port. After connecting the workstation, you find that the workstation cannot get an IP address from the DHCP server. You check the link and status lights and see that the connection is working properly. A ping to the loopback address on the workstation succeeds. No other computers seem to have the problem.

Which of the following is the most likely cause of the problem?
A. Incorrect default gateway setting
B. Incorrect VLAN assignment
C. Switching loop
D. Half-duplex setting on the switch and workstation