A、Because it was just ordinary bread. B、Because it contains more calorics in the whole loaf. C、Because the total number of calor

(19)The appeal of advertising to buying motives can have both negative and positive effects. Consumers may be convinced to buy a product of poor quality or high price because of an advertisement.(20)For example, some advertisers have appealed to people’s desire for better fuel economy for their cars by advertising automotive products that improve gasoline mileage. Some of the products work. Others are worthless and a waste of consumers’ money.
     (21)Sometimes advertising is intentionally misleading. A few years ago a brand of bread was offered to dieters with the message that there were fewer calories in every slice. It turned out that the bread was not dietetic, but just regular bread.(21)There were fewer calories because it was sliced very thin, but there were the same number of calories in every loaf.
    On the positive side, emotional appeals may respond to a consumer’s real concerns of fire insurance. Fire insurance may be sold by appealing to fear of loss. But fear of loss is the real reason for fire insurance.(22)The security of knowing that property is protected by insurance makes the purchase of fire insurance a worthwhile investment for most people. If consumers consider the quality of the insurance plans as well as the message in the advertisements,(22)they will benefit from the advertising.
    Each consumer must evaluate his or her own situation. Are the benefits of the product important enough to justify buying it? Advertising is intended to appeal to consumers, but it does not force them to buy the product. Consumers still control the final buying decision.
Questions 19 to 22 are based on the passage you have just heard.
19. What is this passage mainly about?
20. What does advertising do to persuade the consumer to buy worthless products?
21. Why is the bread advertisement misleading?
22. For most people, why is it worth buying fire insurance?