JacksFright company is planning to open warehouses in four cities: New Jersey, San Francisco, Milwaukee, and Charlotte. Each warehouse can ship 100 units per week. The weekly fixed cost of keeping each warehouse open is $400 for New Jersey, $500 for San Francisco, $300 for Milwaukee, and $150 for Charlotte. Region 1 of the country requires 80 units per week, region 2 requires 70 units per week, and region 3 requires 40 units per week. The costs (including production and shipping costs) of sending one unit from a plant to a region are shown in the table below: o (S) Region 1 Region 2|Region 3 From New Jersey San Francisco Milwaukee Charlotte 20 40 50 48 15 26 26 35 18 24 50 35 We want to meet weekly demands at minimum cost, subject to the preceding information and the following restrictions: (a) If the New Jersey warehouse is opened, then the San Francisco warehouse must be opened. (b) At most two warehouses can be opened. (c) Either the Charlotte or the San Francisco warehouse must be opened