It’s not. The best option for getting links to unanswered topics might be to use a Data Explorer query. There might be an example query for that on Meta, but I’m not finding one when I search for it.
Another option is to install the Unanswered Filter theme component: Unanswered Filter. It adds a dropdown item to the site’s navigation menue that allows you to filter topic lists to only display unanswered topics.