You will always have more than one category from which to choose; obviously, you may know more about some categories than others! In the first two rounds, you should pick your “best” category from the options available, no matter what the point value might be. You can afford to choose less valuable questions, because the score ladder is easy to fill on those levels. In later rounds, though, you might need to take some risks: you’ll need to correctly answer more than one higher-value question in order to complete each level.