Answer:
ok the answer should be A.
Explanation:
you transform the coordinates from (x,y) to (-y,x)
this means to flip the coordinates like bring y up front and change its sign and take x to the initial y position.
for example if (-1,9) when you do the transformation you get (-9,-1). you take initial -1 to the right and bring 9 to left and change its sign.
when you are done you can see that the x axis coordinates are the same but the y axis coordinates are the direct opposite. this means that after the transformation the triangle would look like the mirror image of the original triangle.