<h3>
Answer:</h3>
D. S(-a, -a), T(-a, a), W(a, a), Z(a, -a)
<h3>
Step-by-step explanation:</h3>
Point S is in the 3rd quadrant, where both coordinates are negative. That eliminates choices A and B.
The distance between points is 2a, so the distance from a corner point to either axis is "a". That is, the magnitude of any coordinate value is "a", not "2a." That eliminates choice C.
Remaining is the correct choice: D.