[单项选择]In a competitive economy, the consumer usually has the choice of several different brands of the same product. Yet underneath their labels, these products are often nearly identical. One manufacturer’’s toothpaste tends to differ very little from another manufacturer’’s. Two different brands of shampoo may vary only in scent or color. And the tobacco in two different brands of cigarettes frequently comes from the same fields. This close similarity means that a shopper often has little reason to choose one brand over another. Thus, manufacturers are confronted with a problem--how to keep sales high enough to stay in business. Manufacturers solve this problem by advertising. Through advertising, each manufacturing company tries to convince consumers that its product is special. To do this ,the companies try to appeal to consumers in various ways. In fact, advertisements may be classified into three types according to the kind of appeals they use. 　　One type of advertisement tries to app
A. to recommend products scientifically superior to others.
B. to make scientific statements to attract potential buyers.
C. to impress consumers with scientific truth about the product.
D. to associate laboratory findings with the ingredients of the product.