All of the above factors affect electric force. Specifically, the electric force between two charged objects is influenced by:
- Whether the charge on an object is positive or negative (like charges repel, while opposite charges attract).
- The amount of the electric charge (greater charge results in a stronger force).
- The distance between two charged objects (the force decreases as the distance increases, according to Coulomb's law).
Therefore, the correct response is All of the above.