A wheat transportation problem involves the following costs, supply, and demand (in tons): To (Cost) From City A City B City C City D Supply Location 1 $500 $750 $300 $450 16 Location 2 650 800 400 600 18 Location 3 400 700 500 550 20 Demand 12 14 16 18 Solve the model by using the computer and find the optimal solution and the costs at each optimal point. At optimum, ____ tons of wheats are transported from Location 2 to City C with the transportation cost of ____. zero tons; $0 4 tons; $3,200 16 tons; $6,400 5 tons; $2,000 None of the above.