Answer:
Dilation.
Explanation:
From the given picture , it can be seen that the size of trapezoid P'Q'R'S' is decreased from trapezoid PQRS .
Reflection , rotation and translation are rigid motions that produces congruent images and do not change the size of the shapes.
But dilation is not a rigid motion because it changes the size of the shape by using a scale factor.
Hence, the transformation maps trapezoid PQRS onto trapezoid P'Q'R'S' is "Dilation".