Which sentence fully illustrates that polygon abcd is congruent to polygon pqrs?

Ans: Polygon ABCD maps to polygon PQRS through a reflection only.

Explanation:
As you can see in the figure that the polygon PQRS is the reflection of the polygon ABCD. If we reflect the polygon ABCD on the x-axis, we would get the polygon PQRS. Congruency means that both shapes have the same measure, which in this case, both these shapes have the same measure. Therefore, we can say that polygon ABCD maps to polygon PQRS through a reflection only in order to be congruent to each other.