When a station communicates on the network for the first time, which of the following...

The RARP protocol sends out a packet, which includes its MAC address and a request to be informed of the IP address that should be assigned to that MAC address.

ARP does the opposite by broadcasting a request to find the Ethernet address that matches a known IP address.

ICMP supports packets containing error, control, and informational messages (e.g. PING).

UDP runs over IP and is used primarily for broadcasting messages over a network.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 87.