sophia is dilating a figure.  one of her pre-image points with coordinates (-3, 5)  has an image with coordinates (-9, 15). If one of the other image points has coordinates (3, 1), what are the coordinates of its pre-image point? 
A. (9, 3) 
B.  (1, 1/3) 
C. (1,3) 
D. (-3,-1)