Adock worker pulls two boxes connected by a rope on a horizontal floor, as shown in the figure . all the ropes are horizontal, and there is some friction with the floor. make a free-body diagram of the box b.

The worker pulls the boxes. The force (F) on box B acts towards right direction. The weigh (mg) of the box acts in the downward direction where as reaction force -Normal force (N) acts in the upward direction.

The contact surface between box  and ground is not smooth and hence friction (f ) would act in the opposite direction of the motion of the box. Tension (T) exist in the rope connecting the two boxes.

The free body diagram of box B is attached below showing all the forces acting on it.

it is easily magnetized.

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this