Answer:
a. rotation; then reflection across x
Step-by-step explanation:
The transformation shown is a reflection across the y-axis.
The first part of each answer choice is a rotation 180°. That rotation is fully equivalent to reflection across both the x- and y-axes, in either order. In order to have a net effect of reflection across the y-axis, the reflection across the x-axis must be cancelled--by another reflection across the x-axis.
The reflection across y shown is equivalent to ...
rotation 180° followed by reflection across the x-axis.
