Answer: A. 60 N to the right.
Explanation:
To determine the additional force that Marcus needs to apply in order to overcome Kelli's force, we need to find the net force acting on the refrigerator.
The net force is the sum of all the forces acting on the object. In this case, the forces are acting in opposite directions, so we need to subtract the force applied by Kelli from the force applied by Marcus.
Net force = 300 N to the right - 360 N to the left
Net force = -60 N
The negative sign indicates that the net force is to the left.
Therefore, Marcus needs to apply an additional force of 60 N to the right in order to overcome the force applied by Kelli.