What is the reaction effect of the following action effects?

a) Earth orbits the sun
b) Ball accelerates downward
Thank YOu.

(a) sun "wobbles" about its center of mass due to the force exerted upon it by the Earth and other planets, especially Jupiter.

(b) The Earth moves towards the ball as it falls, by an amount equal to about one-millionth of the distance that the ball falls. The motion will probably be undetectable because of other objects rising or falling near the Earth at the same time.