What set of transformations could be applied to rectangle ABCD to create A″B″C″D″?

Answer:
the third option : reflected over the x-axis and rotated 90° counterclockwise.
Step-by-step explanation:
a rotation by 180° would result in the same orientation as the original - just mirrored across the origin. but since the orientation changed, the answer options with 180° are out.
and if it was reflected over the y-axis, then the rotation would have to be clockwise.