Answer:
A reflection is a transformation in which the figure flips over a line of reflection. The reflected figure is a mirror of the original image. Each pair of points, original and reflected, will be the same distance from the y-axis or x-axis.
Line AB can be reflected over the y-axis in this manner.
image 1:
image 2:
A similar process can be used to reflect line CD over the y-axis.
image 3:
The reflected lines are shown in the graph below.