The graphical method is a purely visual way of solving an LPP, it works only with two decision variables plotted on x and y axes. To draw the boundary line of a constraint such as \( 2x + 3y \le 6 \), we simply treat it as the straight line \( 2x + 3y = 6 \), find its intercepts, and plot it, then shade the side that satisfies the inequality. There is no algebraic manipulation of the constraint matrix here, so there is no need for slack, surplus or artificial variables at all, those belong to the simplex method where constraints are converted to a system of equations for row operations. So in the graphical method, inequalities are simply assumed to be equations for the purpose of plotting, which is option 4.