Concept:An unpaid seller has certain legal rights to recover payment for goods already delivered or sold.Explanation:When goods are sold but the price is not paid, the seller becomes an unpaid seller.One important right of an unpaid seller is to bring a court action against the buyer for the amount owed.This is a legal remedy to recover the contract price from the debtor.The other options listed are not recognised rights of an unpaid seller under the law.Answer:A. Sue a debtor for the amount owed.