Which command displays the current status of a designated unit?

The command that displays the current status of a designated unit is indeed "systemctl status." This command is part of the systemd system and service manager, which is used in many modern Linux distributions to manage system services and controls. When executed, it provides detailed information about the specified unit, including its active state, whether it is running or stopped, any loaded configuration or environment settings, and the most recent log entries related to that unit.

For a unit specified by the user, such as a service, "systemctl status" returns valuable information that is necessary for troubleshooting or monitoring the service's performance and state. This can include information about related services and processes, making it an essential tool for Linux administrators.

Other options provided do not represent valid commands in the context of querying unit statuses with systemctl, which is why they do not serve the purpose described in the question.