The answer to this question is the dilation with a scale factor of 0.5. With a rotation, the size of the figure stays exactly the same - it is just turned. With the reflection, the size also remains the same, it will just be flipped down or up (over/across the x-axis). And, a translation does also NOT change the size of the figure. It only moves the figure to a new position. The dilation will create a similar figure (same shape, but NOT the same size). In this case, the new figure will have side lengths half of the original figure.
