A technician is hardening a company file server and needs to prevent unauthorized LAN devices from accessing stored files. Which of the following should the technician use?

A software firewall on the server can be configured to block or allow network connections based on source IP address, port number, and application, thereby preventing unauthorized LAN devices from establishing connections to shared files.

Password complexity rules enforce strong passwords for user accounts, which is a different security layer than network access control for devices.

An antivirus application protects against malware, but it does not prevent legitimate but unauthorized devices from attempting to connect to the server's shared resources.

Anti-malware scans identify and remove malicious software, which is different from controlling network access for devices.