When attempting to connect to a remote system, a long delay is experienced before the login prompt is displayed. Which of the following is the most likely cause of this issue?

A missing /etc/resolv.conf causes the system to skip DNS entirely and fall back immediately to /etc/hosts, resulting in a fast failure rather than a prolonged timeout delay.

When an inbound remote connection is received, the remote system performs a reverse DNS lookup on the client IP address for authentication and logging purposes. An invalid entry in /etc/resolv.conf - such as an unreachable DNS server IP - causes the resolver to time out after multiple retry attempts before the login prompt is presented, producing the observed delay.

The remote system lacking an entry for itself in /etc/hosts affects local hostname resolution but does not introduce a delay during inbound connection authentication.

An invalid hostname for the server itself in /etc/hosts may cause local resolution problems but does not produce the characteristic multi-second timeout caused by failed reverse DNS lookups.