How do you determine the default job running in a console session?

To determine the default job running in a console session, using the plus sign (+) represents the current default job managed by the shell. In the context of job control in Unix-like operating systems, the plus sign indicates the job that is currently in the foreground or the last job that was executed in the foreground. This job is identified as the default because it's the one that will react to signals sent by the shell, such as stopping or terminating activities.

The jobs command shows all the jobs associated with the current shell session but does not indicate which one is the default. The fg command is used to bring a background job to the foreground but does not provide information about which job is currently the default. Lastly, the ps command displays all the processes running on the system, but it doesn't specify which job is associated with the user's console session or which is the foreground job. Thus, the correct choice to determine the default job running in a console session is represented by the plus sign.