Internet Relay Chat (IRC) is a real-time communication protocol. When a client connects to an IRC server, it must first identify itself using two mandatory commands:

NICK – Specifies the nickname the user wants to use.

USER – Provides user information such as username, hostname, and real name.

These are the very first commands required to establish presence on the IRC network.

From CEH v13 Official Courseware:

Module 7: Social Engineering

Module 19: IoT and Other Emerging Threats (includes botnets and IRC)

CEH v13 Study Guide states:

“When connecting to an IRC server, the client must first send the NICK and USER commands to register the session. Without these, the server will not establish a full connection.”

Incorrect Options:

B, C, D: LOGIN and PASS are not valid IRC protocol commands in this context.