Based on past experience, Moss Company has developed the following budget formula for estimating its shipping expenses. The company's shipments average 12 lbs. per shipment: Shipping costs = $16,000 + ($0.50 x lbs.shipped). The planned activity and actual activity regarding orders and shipments for the current month are given in the following schedule: Plan Actual Sales orders 800 780 Shipments 800 820 Units shipped 8,000 9,000 Sales $ 120,000 $ 144,000 Total pounds shipped 9,600 12,300 The actual shipping costs for the month amounted to $21,000. The appropriate monthly flexjble budget allowance for shipping costs for the purpose of performance evaluation would be: $20.920 O $22.150 $20,680 O $20,800