Answer:
A. Distance over which the force is applied
Step-by-step explanation:
As we know that in pulley system the mass of the car is balanced by the tension in the string
so here we will have

so here in order to decrease the force needed to lift the car we have to increase Distance over which the force is applied
So here if we increase the distance over which force is applied then it will reduce the effort applied by us in this pulley system as the torque will be more if the distance is more.