What netstat command would best allow an administrator to determine the service responsible for a listening socket?

The netstat command that would best allow an administrator to determine the service responsible for a listening socket, including the associated process, is:

sudo netstat -lnp

The -l flag shows listening sockets, the -n flag displays numerical addresses and ports, and the -p flag shows the associated process and its process ID (PID). By running this command with superuser privileges (sudo), you can see the service responsible for each listening socket, as well as the process associated with it.