Which of the following commands would you use to check the current active users in the system?

The command used to check the current active users in the system is "w". This command provides a summary of who is currently logged on and what they are doing. It shows information such as login names, terminal lines, login time, idle times, and the commands currently being run by each user. This makes it a valuable tool for system administrators to monitor user activity and system performance.

The other commands listed perform different functions. For instance, "ifconfig" is primarily used for network interface configuration and doesn't provide information about user sessions. "vipw" is a command for safely editing the password file, which contains user account information, but it does not display active users. Lastly, "ip link set" relates to managing network devices and their settings, offering no information regarding logged-in users. Thus, "w" stands out as the appropriate choice for checking active users.