Final answer:
The electrostatic force is inversely proportional to the square of the distance between charges. It can be either attractive or repulsive depending on whether the charges are like or opposite.
Step-by-step explanation:
For electrostatic forces, the force is inversely proportional to the square of the distance between the charges, as described by Coulomb's law. This means that the force will increase as the distance between charges decreases, and vice versa. The question has multiple parts which may seem confusing, but breaking it down, electrostatic forces can be both attractive and repulsive; they depend on the types of charges involved. Two like charges (both positive or both negative) will repel each other, resulting in a repulsive force.
Conversely, two opposite charges (one positive and one negative) will attract each other, resulting in an attractive force. Therefore, answer (d) 'Force is inversely proportional to distance' is the most accurate. However, to be precise, it is inversely proportional to the square of the distance. The force is also proportional to the product of the charges involved, not independent of them.