Exhibit:  You are the administrator of Company.com's network.  Company.com has recently upgraded its network to a 100 Mbps standard. And all Windows 2000 Professional computers in Company's main office has been upgraded with new 10/100 Mbps  network interface card (NIC). All computers have been configured with TCP/IP protocol settings so that IP and DNS settings are obtained automatically from a DHCP services server. A user has reported that he cannot access the network. You view the network adapters node in Device Manager as shown in the Device Manager window. See exhibit. You want this computer to communicate on the network using the least amount of administrative effort. What should you do?（）

• A、Configure IP address settings manually.
• B、Replace the network adapter
• C、Disable TCP/IP filtering for all network adapters.
• D、Enable the network adapter.
• E、Enable IEEE 802.1x authentication