THE QUESTION HAS DIFFERENT VARIABLES THAN THOSE THAT ARE ON CHEGG!! Please answer b) IN DETAILS. The more it gets into details, the better for me. Thank you

4. Rent'R Cars is a multisite car rental company in the city. It is trying out a new "return the car to the location most convenient for you" policy to improve customer service. But this means that the company has to consistently move cars around the city to maintain required levels of vehicle availability. The supply and demand for economy cars, and the total cost of moving these vehicles between sites are shown as follows. D E F G Supply From $9 S8 S6 $ $ 55 A 50 9 8 8 0 B 40 5 3 3 10 75 Demand 50 60 25 30 a. Find the solution that minimizes moving costs using Linear Programming in Microsoft Excel. List your decision variables, objective functions and constraints here. Upload the Excel file to blackboard system, too. (10 points) b. What would you have to do to the costs to assure that A always sends a car to D as part of the optimal solution? (5 points)