53. Supermarkets are trying out new computers that make shopping carts more intelligent(具备智能的)．They will help shoppers find paper cups or toilet soap, and keep a record of the bill.The touch-screen devices(触摸屏装置) are on show at the Food Marketing Institute’s exhibition here this week, “These devices are able to create value and get you around the store quicker,” said Michael Alexander, manager of Springboard Retail Networks Inc., which makes a smart cart computer called the Concierge.Canadian stores will test the Concierge in July．A similar device, IBM’s “Shopping Buddy”, has recently been test-marketed at Stop & Shop stores in Massachusetts.Neither device tells you how many fat grams or calories are in your cart, but they will flash you with items on sale．The idea is to make it easier for people to buy, not to have second thoughts that maybe you should put something back on the shelf.“The whole model is driven by advertisers’ need to get in front of shoppers,” said Alexander．“They’re not watching 30-second TV ads anymore.”People can use a home computer to make their shopping lists．Once at the store, a shopper can use a preferred customer card to start a system(系统) that will organize the trip around the store．If you’re looking for toothpicks, you type in the word or pick it from a list, and a map will appear on the screen showing where you are and where you can find them.The device also keeps a record of what you buy．When you’re finished, the device figures out your bill．Then you go to the checker or place your card into a self-checkout stand and pay.The new computerized shopping assistants don’t come cheap．The Buddy devices will cost the average store about $160,000, and the Concierge will cost stores about $500 for each device.The underlined word “they” (paragraph 1) refers to ______.
(A)supermarkets
(B)shop assistants
(C)shopping carts
(D)shop managers