HELP! Triangle ABC is being dilated with the center of dilation at the origin. The image of C, point C prime, has coordinates of (7.2, 3.6). What is the scale factor of the dilation and what are the coordinates of point A prime?

On a coordinate plane, triangle A B C has points (negative 3, 3), (1.5, 9), (6, 3). C prime is (7.2, 3.6).
The scale factor is 1.2 and the coordinates of point A prime are (–2.5, 2.5).
The scale factor is StartFraction 5 Over 6 EndFraction and the coordinates of point A prime are (–2.5, 2.5).
The scale factor is 1.2 and the coordinates of point A prime are (–3.6, 3.6).
The scale factor is StartFraction 5 Over 6 EndFraction and the coordinates of point A prime are (–3.6, 3.6).