Which command could be considered for checking system information in Linux?

The command "who" is used in Linux to check system information related to users currently logged into the system. When executed, it provides a listing of all users and the terminal they are logged into, which includes details like the login time and originating IP address or hostname if applicable. This information can provide insights into the user activity on the system, contributing to a broader understanding of its status.

In contrast, the command "ls" is used to list files and directories in the current directory, providing no information about system users or overall system health. The command "pwd" displays the present working directory and is primarily focused on navigation rather than system status. The command "mkdir" is used to create new directories, which does not relate to retrieving any system information. Therefore, "who" stands out as the appropriate option for checking the state of user activity on a Linux system.