An administrator needs to test that a service is responding to external requests. Which of the following tools can be used to accomplish this task?

Ping tests ICMP connectivity to a host, which only confirms basic network reachability, not whether a specific application service is active and responding on a port.

Traceroute maps the network path to a destination and determines intermediate hops, but it does not test if a particular service is running or responding on that destination host.

Telnet can be used to establish a direct TCP connection to a specific port on a remote host, which is effective for testing if a service is listening and responding. By attempting to connect to the service's port (e.g., 'telnet example.com 80'), an administrator can verify if the service is active and accepts incoming connections.

Ipconfig/ifconfig displays the network configuration of the local machine, such as IP addresses and network interfaces, and cannot be used to test external service responsiveness.