The answer is B, or the second option with 5 newtons on the left and 4 newtons on the right.
This would be the answer because there are 5 newtons forcing the given object to the right while there are 4 newtons forcing the object to the left. Because 5 is greater than 4, the object would accelerate to the right in this model with 1 newton more of force than it would to the left.
