the following four questions: (a) How does the optimal objective value change if Plant B has 1000 more units ready to be shipped out? (Recall that our shipment quantities are defined in thousands of units (b) How does the optimal objective value change it Warehouse 1 requires 1000 more units? (c) How does the optimal objective value change if the shipment cost from Plant B to Warehouse 2 decreases from $750 to $700? (d) By how much does the cost of shipping from Plant B to Warehouse 3 need to decrease before it becomes optimal to ship a positive number of units on that route