The answer is option D.
In order to solve for the slope, you have to use the equation (y2 - y1)/(x2 -x1).
In this specific question, we have two points: (-9, -6) and (3, -9). If we use the equation above:
(-9 - (-6))/(3 - (-9))
(-9 + 6) / (12)
-3/12
-1/4
-T.B.