An administrator is asked to harden a Linux server after installing the OS. Which of the following should the administrator do FIRST?

Immediately installing the latest OS patches is the foundational first step in hardening any server, as it remediates known security vulnerabilities and bugs, establishing a secure baseline before further configuration.

Setting up a personal firewall is an important hardening step but should typically follow the application of OS patches to ensure the underlying system itself is protected against known exploits first.

Disabling a Host Intrusion Detection System (HIDS) would weaken the server's security posture, as HIDS are designed to monitor for malicious activities.

Enabling Wake-on-LAN (WOL) is a power management feature and is not directly related to server hardening; in some cases, if not properly secured, it could even introduce security risks.