A server administrator needs to check remotely for unnecessary running services across 12 servers.

 The tool that the administrator should use to check for unnecessary running services across 12 servers is a port scanner. A port scanner is a tool that scans a network device for open ports and identifies the services or applications that are running on those ports. A port scanner can help detect any unauthorized or unwanted services that may pose a security risk or consume network resources. A port scanner can also help troubleshoot network connectivity issues or verify firewall rules.