2. 0, She walked a mile and then walked home, which made her total displacement in the end 0
3. A, By driving west from the starting point. I had to make a graph in ms paint to visualize it better, which i attached.
4. 4 meters. The ball rolled up the hill 5 meters, then down 9 meters. Simply subtract the two and you have -4 meters. The question asks for the overall displacement of the ball, so the negative doesn't count.
I hope these answers are what you're looking for :)