Introduction to Management Science (Ch. 3, Q. 24 a). I understand how the constraints were formed based on the information provided. However, can you please explain how the optimal solution of Stock A = 333.3, Stock B = 0, Stock C = 833.3 and Stock D = 2,500 was calculated? I do not know how to use a graphical solution method with 4 variables to calculate an optimal solution. I have included an image to show the problem. Thank you!