A point charge +0 is located on the x axis at x = a, and a second point charge -0 is located on the x axis at x = -a. A Gaussian surface with radius r = 23 is centered at the origin. The flux through this Gaussian surface is Select one: none of the above greater than zero zero because at every point on the surface the electric field has no component perpendicular to the surface. zero because the negative flux over one hemisphere is equal to the positive flux over the other. zero because the electric field is zero at everyr point on the surface