Based on Past Experience, Moss Company Has Developed the Following

Based on past experience, Moss Company has developed the following budget formula for estimating its shipping expenses:
Shipping costs = $16,000 + ($0.50 × lbs. shipped) . The company's shipments average 12 lbs. per shipment.
The planned activity and actual activity regarding orders and shipments for the current month are given in the following schedule:
$$\begin{array} { l r r } & \text { Plan } & { \text { Actual } } \\\text { Sales orders } & 800 & 780 \\\text { Shipments } & 800 & 820 \\\text { Units shipped } & 8,000 & 9,000 \\\text { Sales } & \$ 120,000 & \$ 144,000 \\\text { Total pounds shipped } & 9,600 & 12,300\end{array}$$
The actual shipping costs for the month amounted to $21,000. The appropriate monthly flexible budget allowance for shipping costs for the purpose of performance evaluation would be: (CMA adapted)

A) $20,680.
B) $20,920.
C) $20,800.
D) $22,150.