Answer:
Vertical translation
Explanation:
Let's compare each point to its corresponding point in the image.
First, look at point A. Look at point A'.
With respect to the shapes ABCD and A'B'C'D', they are in the same position (in between B/B' and D/D'; across from C/C').
If you look at the image again, you'll find that the shape A'B'C'D' is not a rotated version of ABCD.
Thus, we can rule out the option "90° clockwise rotation."
A reflection across the x-axis indicates that A'B'C'D' and ABCD would be symmetrical across the x-axis (a horizontal line).
Because ABCD and A'B'C'D' are not symmetrical across a horizontal line, we can also rule out "Reflection across the x-axis."
Now, look at the position of A'B'C'D' with respect to ABCD. It's directly next to ABCD. In other words, it was shifted sideways.
Translations are basically just shifts.
Recall that horizontal means up and down, while vertical means side to side.
Since this is a sideways shift, we can conclude that the translation was:
a vertical translation.