Concept:A franking machine is a device used by organisations to print postage stamps directly on mail.Explanation:The post office supplies this machine to approved organisations.It imprints stamps or a postage mark on letters and parcels.It also calculates the total postal charge automatically.Among the options, a vending machine sells goods, a shredding machine cuts paper, and an automated teller machine dispenses cash.Only a franking machine performs the function described in the question.Answer:D. franking machine