You plot the first point on the y-axis at 15 units up. Then you follow the direction of the slope.
The slope is: -5/1
So from your first point on the y-axis, go down 5 units and to the right 1 unit. Do this multiple times after you plot your new point. After this you may draw a line with an arrow to connect the dots.
If a question has four possible answers, and you are strictly guessing regarding which of them is correct, then the chances of your choosing the correct one from the four is 1 in 4, or 0.25.
