An administrator needs to verify what ports are listening on an operating system. Which of the following tools can be used to accomplish this task?

Telnet is used to test connectivity to a specific port on a remote host but cannot enumerate all listening ports on a system.

Netstat (network statistics) is a built-in command-line utility that reports active TCP and UDP connections along with the ports on which the local system is listening, directly satisfying the requirement to verify which ports are open on an operating system without requiring any external traffic.

A packet sniffer captures network traffic passing through an interface but cannot enumerate all ports the local OS has open and listening without active traffic being present on each port.

Ifconfig displays network interface configuration such as IP addresses and MAC addresses, not the ports that processes have bound and are listening on.