A problem can be solved by the methods of statics Only if th

A problem can be solved by the methods of statics: Only if the object is at rest. If the velocity of the object is constant, even if the value of the velocity is not zero. Regardless of whether the velocity is constant. Only if the acceleration of the object is not zero.

Solution

In statics, the object is in the equilibrium. Equilibrium means the all the forces which act on the object, the all sum to zero. So if the force is zero then from Newton\'s second law, the acceleration must be zero. Hence fourh option is correct.