Geometry: On the set of axes below, ABC is drawn and passed through A(-2,6) and B(4,0). If CD is the image of AB after a dilation with a scale factor of 1/2 centered at the origin, which equation represents CD?
1. y = -x + 4
2. y = -x + 2
3. y = - 1/2x + 4
4. y = - 1/2x + 2