Answer:
Reflecting over the x-axis and then reflecting over the line y = x.
Explanation:
A rotation 90° counterclockwise will map every point (x, y) to (-y, x).
Since the x- and y-coordinates are switched, this is not a reflection across the x-axis followed by a reflection across the y-axis.
Since the y-coordinate is negated and the x- and y-coordinates are switched, this is not a translation.
Reflecting across the x-axis will negate the y-coordinate, giving us (x, -y). Following this with a reflection across y=x will switch the coordinates giving us (-y, x). This is the correct transformation.