The best option for enhancing security in a scenario where multiple services are running is to disable any unnecessary services. Disabling unnecessary services reduces the attack surface of the server by eliminating potential entry points for attackers. Enabling a firewall may add a layer of protection, but does not directly address the risk associated with running unneeded services. Changing service default ports can obfuscate the services from basic scans, but does not provide a substantial security improvement, as determined attackers can still discover and exploit services running on non-standard ports. Applying updates and patches is essential for security; however, this action does not inherently address the risk associated with having unnecessary services running.