Smith & Co. carried on business as a wholesaler and operated a fleet of delivery trucks to supply its customers. The company found the cost of maintaining the delivery equipment excessive and decided to sell its fleet of trucks. The company arranged to have all delivery work handled by a local cartage company and advertised for a buyer for its delivery equipment. Eventually, Smith & Co. found a buyer willing to purchase the trucks for $180,000, and the sale was immediately completed. Some months later, a creditor of Smith & Co. discovered that it no longer possessed a fleet of trucks. The creditor complained that the trucks should not have been sold without his permission, even though he was only an unsecured creditor to whom Smith & Co. owed $6,000 on a trade account. What are the rights of the parties in this case? What steps should Smith & Co. have taken to avoid creditor complaints?