The answer is C because if you turned Figure Q 90 degrees clockwise, it matches Q', thus a counterclockwise rotation of 270 degrees around the origin had to have been applied.
A is disqualified because if it had been rotated 90 degrees counterclockwise, it would be in the top left quadrant.
B is disqualified because if it was rotated 180 degrees about the origin, it would be in the bottom left quadrant.
D is disqualified because if rotated 270 degrees about the origin it would be in the top left quadrant, same as answer A.
