The following activity rates are associated with moving rail cars by train: $4 per gross ton mile; $50 per rail car switch; $200 per rail car. A train with 20 rail cars traveled 100 miles. Each rail car carried 10 tons of product. Each rail car was switched two times. what is the total cost of moving this train?

a. $5,400 b. $44,100 c. $10,000 d. $86,000