In stage direction a animals roar would go in sound. It would not go in movement because movement would involve the animal 'moving' not roaring. It would not be props because props are items characters in the story would have to use which not includes the sound of a animals roar. It's also not option D setting because setting would be a place, where the story takes place.
Answer: Because if you are uncertain of what's happening then you don't know how to deal with the situation. So in order to compensate for that not knowing, you take a risk.