Answer:
A. The rotation (x, y) -> (-x, -y)
Explanation:
Let's call the point on the black triangle at point (-2, 1) "point A." The corresponding point to point A on the gray triangle is at point (2, -1). Let's call this point "point A'" or "point A prime." We can see that the x coordinate changed from -2 to 2. The y coordinate changed from 1 to -1. Thus, the answer is (x, y) -> (-x, -y) because the x changed from negative to positive and the y changed from positive to negative. I hope this helps :)