How to make an object not clickable?

I have a game made in UE4 where bubbles with french verb conjugations scroll past a bubble with the subject you are conjugating in it. The player must click incorrect answers as they scroll past to delete them and ensure that only the correct answer scrolls past the bubble. The problem is, the main bubble that has the subject in it (not a scrolling bubble) can be clicked and deleted, thus making the game un-winable. Is there any way to make it so this bubble cannot be deleted?