The graph is rotated about the origin. The initial location is the upper graph, located in quadrant II. It ends at quadrant III. We can see it has been rotated 90° counter clock-wise. It can be seen clearer if one draws a line from the origin to any point of the graph; let's say point Q, and then a new line from the origin to the new location of that point: Q'. Those two lines will form an angle of 90°, as shown in the figure below. The same happens if you draw a line towards any of the 4 points.
The rotation is counter clock-wise, which is exactly the direction taken for positive rotations; then, the answer will be the first option:
[tex]R_{0,90^o}[/tex]
Then, the transformation is a rotation of 90° counter clock-wise about the origin.
