How is Cisco IOS commonly used for configuring and managing network devices?

wht number is the answer here?

$1,$ By connecting to a central management server and making configuration changes.

$2.$ By executing commands in the command$-$line interface $($CLI$).$

$3.$ By utilizing a mobile app specifically designed for Cisco IOS configuration.

$4.$ Through a web$-$based graphical user interface $($GUI$)$ accessed via a web browser.