The figure shows two triangles on the coordinate grid: What set of transformations is performed on triangle ABC to form triangle A′B′C′?

a.
A translation 5 units down, followed by a 180-degree counterclockwise rotation about the origin

b.
A translation 5 units down, followed by a 270-degree counterclockwise rotation about the origin

c.
A 180-degree counterclockwise rotation about the origin, followed by a translation 5 units down

d.
A 270-degree counterclockwise rotation about the origin, followed by a translation 5 units down