Answer:
The above answer is incorrect.
Explanation:
The answer would be Option D.
A clockwise rotation about the origin basically means turning the shape 90°, and moving it to the left (in this scenario.)
We see that the red triangle is in the first quadrant, and that the green polygon is in the second quadrant. If we rotate the red triangle about the origin clockwise, it would be perfectly in the missing portion of the green square, making is a perfect square.