The Cost-Less Corp. supplies its four retail outlets from its four plants. The shipping cost per shipment from each plant to each retail outlet is given below. Source/destination D E F A 5 6 4 B 6 9 10 C 7 8 9 Plants A, B, and C make 100, 200, and 200, shipments per month, respectively. Retail outlets 1, 2, and 3 need to receive 200, 140, and 160, shipments per month, respectively. The distribution manager now wants to determine the best plan for how many shipments to send from each plant to the respective retail outlets each month. His objective is to minimize the total shipping cost. Solve the problem using the northwest corner method. please help me​