A positively-charged rod is held near to, but not touching, an uncharged metal sphere. The sphere is briefly now connected to earth. The rod is removed.
Which statement about the charge on the sphere is correct?
It is charged negatively because negative charges have moved from earth to the sphere.
It is charged negatively because positive charges have moved from the sphere to earth.
It is charged positively because negative charges have moved from the sphere to earth.
It is charged positively because positive charges have moved to earth from the sphere
