Final answer:
The minimum force required to move the filing cabinet across the ground to the start of the ramp is a negative force.
Step-by-step explanation:
To determine the minimum force required to move the filing cabinet across the ground to the start of the ramp, we need to consider the forces acting on the cabinet. When the cabinet is at rest on the ground, the only force acting on it is the force of gravity. However, as we start pushing the cabinet, a frictional force arises which opposes the motion. The minimum force required to overcome this frictional force is equal in magnitude, but opposite in direction.
Therefore, the minimum force required is negative force (d). It is important to note that the actual value of the force cannot be determined without additional information such as the coefficient of friction between the cabinet and the ground. Without this information, we cannot calculate the exact value of the minimum force.