Your machine’s IP address used to function, but it’s only got the localhost "lo" entry now. What three client-mode commands could you possibly use to get a new DHCP address?

A.
dhcpd

B.
ipconfig

C.
dhclient

D.
pump

E.
dhcpcd

Explanation:
From http://www.faqs.org/docs/Linux-mini/DHCP.html:
Currently there are three different DHCP client programs for Linux: dhcpcd, pump and dhclient.

From the man pages:
dhclient – Dynamic Host Configuration Protocol Client
dhcpcd is an implementation of the DHCP client specified in RFC2131 (when -r option is not specified) and RFC1541 (when -r option is specified). It gets the host information (IP address, netmask, broadcast address, etc.) from a DHCP server and configures the network interface of the machine on which it is running. It also tries to renew the lease time according to RFC2131 or RFC1541 (obsolete).
pump – configure network interface via BOOTP or DHCP protocol