Which falling onject will result in the least kinetic energy when it collides with the ground

The falling object that will result in the least kinetic energy when it collides with the ground is the one with the lowest mass and lowest velocity. This is because kinetic energy is directly proportional to the mass of the object and the square of its velocity. Therefore, the lighter and slower the object is, the less kinetic energy it will have when it collides with the ground.