TimsTabletCo (TTC) produces tablet computers, and it must determine the number of units to be produced during each of the next four months. The following table gives the monthly demand and the monthly cost of producing each unit: MonthDemand (in units)Production Cost (dollars per unit)15000400220006003600020041000300 At the start, before Month 1, TTC has an inventory of 2000 units. Each month, up to 4000 units can be produced. TTC can use the units produced in a particular month in two ways: either use some units to satisfy the demand in the same month, or store some units in inventory for future use. The cost of storing units in inventory is $100 per unit per month. (a) Formulate an LP problem (P) to minimize the total cost of meeting the demands of the next four months. (b) Write the dual LP (D) of (P). (c) Use the Gurobi software to solve (P). Write down the optimal value, and write down an optimal solution