Answer:
10 Newtons to the left.
Step-by-step explanation:
From the attached figure, it can be seen that the force acting towards right and left are
such that,
Let us consider the force acting towards right are positive and negative for towards left.

Let F is the net force acting on the box. It is equal to :


F = -10 N
So, the resultant force acting on the box is 10 N and it is acting towards left. Hence, the correct option is (c).