Final answer:
The scale factor of the dilation is found by dividing the image's x-coordinate by the original x-coordinate of point D, which is 3.
Step-by-step explanation:
To find the scale factor of the dilation, we can compare the coordinates of the original point D(12, -4) with its image's coordinates (36, -12). We must determine how much the x-coordinate and y-coordinate have been scaled by.
Looking at the x-coordinate, the formula for determining the scale factor (k) is:
Original x-coordinate * k = Image's x-coordinate
12 * k = 36
Solving for k gives us:
k = 36 / 12
k = 3
Therefore, the scale factor is C. 3.