Which of the following represents the initial two commands that an IRC client sends to join an IRC network?

Which of the following represents the initial two commands that an IRC client sends to join an IRC network?

A.
LOGIN, USER

B.
USER, PASS

C.
USER, NICK

D.
LOGIN, NICK

Explanation:
A “PASS” command is not required for either client or server connection to be registered, but it must precede the server message or the latter of the NICK/USER combination. (RFC 1459)