InvoiceFreight and Credit TermsTransportation ChargesReturns and Allowancesa.$$3,200$FOB destination, $3/20,$ n$/45$$$40$$$320$b$.$$$7,300$FOB shipping point, $2/5,$ n$/30$$$130$$$80$c$.$$$7,100$FOB shipping point, $3/15,$ n$/45$$$205$$$530$d$.$$$20,000$FOB destination, $2/20,$ n$/60$$$155$$$610$pop$-$up content ends. What is the total amount to be paid in full settlement of invoice$$ a$?$