Being on your knees does not really feel like standing on them.
In many cases you are feeling respect, compassion or even worshipping when you're down on your knees.
Now there have been cases in the news of people being held down by kneeling on their heads or necks, but even those situations look more like ' sitting on' than standing.
That is why the use of ' standing' makes me wonder. Is a specific situation described in this exercise? Is it possible to be sitting on your knees in Bokmål too?