Given the projected demands for the next six months, prepare a level aggregate plan that uses inventory, regular time, and overtime. Regular time is 150 units per month. Overtime can be used as needed. Overtime cost is $30 per unit per period, inventory holding cost is $5 per unit per period, and regular time cost is $20 per unit per period. There is no beginning inventory. Month Demand Forecast Jan 180 Feb 150 March 140 April 150 May 130 June 150 Overtime used for February is 0-5 15-20 o 25-30 0 35-40 None of the above