Answer: Lets number the images from left to right as 1 to 6.
in the part A; rides slowly uphill, then you need to use the 5 image here, because you can see that is a slowly crescent lineal relation.
in the part B: Habib has stopped, so his position is constant, then the first image will describe that his position is constant over the time.
in the part C: if he rides downhill we need a decreasing linear, and fast means that the slope is big, then the correct option is the image number 3.