[单选题] 有200.台主机需要接入,采用什么方式来增强网络安全性? A. Visually verify the MAC addresses and then telnet to the switches to enter the switchport-port security mac-address command. B. Have end users e-mail their MAC addresses. Telnet to the switch to enter the switchport-port security mac-address command. C. Use the switchport port-security MAC address sticky command on all the switch ports that have end devices connected to them. D. Use show mac-address-table to determine the addresses that are associated with each port and then enter the commands on each switch for MAC address port-security.