A systems administrator is looking for operating system information, running services, and network ports that...

To identify a server’s available network ports, running services, and often operating system details, the best tool listed is nmap. In the Network+ (N10-009) toolset, nmap is a standard utility used for network discovery and security assessment, including port scanning (which TCP/UDP ports are open), service enumeration (what application/service is listening on those ports), and service/version detection. With the appropriate scan options and permissions, nmap can also provide OS fingerprinting, which estimates the server’s operating system by analyzing responses to crafted packets.

The other options do not meet all stated requirements. nslookup is used for DNS queries (name-to-IP and record lookups) and does not enumerate ports/services. traceroute (or tracert) maps the path packets take through the network to a destination and helps diagnose routing/latency issues, not services/ports. netstat shows local socket statistics on the host where it is executed (active connections, listening ports, and interface stats), but it does not reliably provide remote OS identification and is not a dedicated service/OS enumeration scanner like nmap.

Therefore, nmap is the correct tool to accomplish the task as described.