The magnitude of the kinetic friction is proportional to the normal force acting between the two bodies. Mathematically,
Where N is the normal force. The proportionality constant μ_k is known as the coefficient of kinetic friction.
The coefficient of kinetic friction is given as,
The force of kinetic friction is always less than the force of static friction. Therefore, the coefficient of kinetic friction is always less than the coefficient of static friction.
Hence, option (3); The coefficient of kinetic friction is not more than the coefficient of static friction is the correct choice.