Two identical metal spheres are touched together and then separated. Which method of charging does simple contact between two conducting objects like this represent?

1. When two conducting objects touch, excess charge can move from one to the other. 2. This direct transfer of charge through contact between conductors is called charging by conduction. 3. Induction only requires a charged object to approach without touching, so it does not describe this case. 4. Polarization is a separation of charge within a single neutral object, and a dielectric is an insulating material placed in a capacitor, so neither names this process. _Source: OpenStax Physics (CC BY 4.0), Ch 18 "Static Electricity", section Transfer and Separation of Charge_