Answer:
Induction
Explanation:
The method used for the charging of spheres is not conduction because during conduction there is a movement of electricity between materials of the sphere without actually charging the materials/sphere
induction is the production of electric charges or an electromotive force by a body or material that already has an electric or magnetic properties and this is a way of getting spheres charged since the spheres do not contain the electric charges already and can get them form materials who possess the ability of providing electric charges
