A positively-charged tabletop may be approximated as an infinite plane producing a uniform electric field. A positively-charged metal sphere levitates motionlessly above the surface of the table. While keeping the rest of the system unchanged, which of the following parameters may be varied without changing the cancelation of gravity by the electrostatic repulsion?

W) The mass of the sphere

X) The radius of the sphere

Y) The charge of the sphere

Z) The strength of the electric field produced by the table
X) THE RADIUS OF THE SPHERE