How much will the objective function improve if we add the Cotton amount by 30 more and 50 more units? Select one: a. We will not be able to tell since the proposed changes are outside the allowable increase or decrease b. $60 improvement for 30 units increase, not able to tell for 50 units increase c. Up to $40 increase or $55 decrease when the changes are in the allowable ranges, but we cannot tell the exact amount of improvement. d. Not able to say for 30 units increase, but $100 improvement for 50 units increase