Which of the following tools is used to configure CUPS?

`lpc` is a line printer control program, primarily used for controlling printer queues and daemons, but not for initial configuration of CUPS printers.

The `lpadmin` command is a CUPS utility used to add, delete, or configure print queues (printers and classes). It allows administrators to set printer options, drivers, and destinations directly from the command line.

`lpr` is used to submit print jobs to the CUPS spooler, not for configuring the printers themselves.

`lpd` refers to the Line Printer Daemon, a service that manages print queues, not a configuration tool for CUPS.

`lpctrl` is not a standard CUPS command for printer configuration.