A dilation transforms an object by making it larger or smaller. When you increase a pre-image to create a larger image, the dilation is called an enlargement. When you decrease the pre-image to create a smaller image, the dilation is called a reduction.
When dilating a triangle the side lengths change because the pre-image is enlarged or reduced to create the image. Therefore, the lengths of each side will change. However, the angle measures of a preimage and its image after dilation do not change (angles do not change in dilation).
with this information we can easily get rid of A & C. betweenness of points don't tell us if the shapes are congruent or not. So therefore D is the answer.
