Triangle PQR has vertices P(3, 5).Q(2, -1). and R(-6, 2).
Triangle P'Q'R' has vertices P'(3, 5) Q'(2, 1). and R'(-6, -2).
Which transformation of triangle PQR produced triangle P'Q'R'?
a reflection across the y-axis
a rotation of 90° counterclockwise around the origin
a rotation of 90° clockwise around the origin
a reflection across the x-axis