A company is developing a linear programming model for a hybrid aggregate plan that combines pure chase demand with level production strategies. The company's demand constraint to ensure that demand is met in period 3 is A. inventory in period 2 + units produced in period 3 - demand in period 3 = inventory in period 3 B. beginning inventory + units produced in period 3 - inventory in period 3 = demand in period 3 C. inventory in period 2 + units produced in period 3 + inventory in period 3 = demand in period 3 D.inventory in period 3 + units produced in period 3 = demand in period 3