When an object experiences multiple forces acting on it, you should start with a free body diagram. Option B.
What is the first thing you should do?
Drawing a free body diagram is the first step to determine the net force when an object experiences multiple forces.
A free body diagram is a simplified representation of an object with all the external forces acting on it represented by arrows. Each force is labeled with its magnitude and direction. By creating a free body diagram, you can visually understand the forces acting on the object and their respective directions.
Once you have the diagram, you can start writting the equations.