Sebastian company manufactures and sells sportswear products. sebastian uses activity-based costing to determine the cost of the customer return processing and the shipping activity. the customer return processing activity has an activity rate of $60 per return, and the shipping activity has an activity rate of $20 per shipment. sebastian shipped 4,000 units of product 1 in 800 shipments (some shipments are more than one unit). there were 90 returns. determine the total activity costs for the return and shipping activities of product 1?.

a. $5,400
b. $21,400
c. $5,500
d. $71,200