Using Botpress Studio visual tool, if the visitor selects a particular option within a card, we want the Bot to navigate to the 'end' node (which is sorted). But, if that same user types anything else we don't want the bot to respond again to that particular user. What's the best way to achieve this? Would be use a user variable? Or store the state of that user within a table? Just wondering what best practise would be? Thanks!