A、They have to buy it. B、They have to apply for it. C、They have to give out their personal information. D、They have to buy a lot

A supermarket club card is a new way for people to save money on items they buy. People used to cut out coupons to save money. Now they use a card that looks like a credit card when they pay for items. Only people with cards can get the lower price.
    To get a card, people must give out their name, address, and other personal information. Everything club card users buy is stored on a computer in a file with their name on it. In the coupon days, no one kept track of the things people bought. Now, computers allow huge amounts of information to be saved.
    In order to save money with the cards, people could lose privacy. So far, the information, or data, is private. But that could change. There are many companies who might be interested in knowing what people buy. For instance, an insurance company might want to know if their clients buy healthy food, or if people buy a lot of medicine from the store.
    People want to make sure there are laws to protect data kept on computers. Stores that use club cards have promised to keep the information private. Some people are afraid the stores might change their minds if companies offered enough money. Some people say the information is worth as much as treasure.
    Credit card companies can’t tell others where you shop. Telephone companies can’t sell a list of numbers you call. But all of this information is on a computer and could be given out. Some people think the store’s promise is good enough. Others aren’t so sure.