Passage Three 　　Our sense of smell, which we normally take for granted, is nowadays being increasingly used for purposes which might surprise us if we were aware of them. One area in which smells are created to achieve particular results is marketing. For some time manufacturers have taken advantage of our sense of smell with regard to household goods. Millions of dollars are spent on product research in the hunt for the right smell as it is believed perfume influences the way consumers perceive a brand. In a survey in the United States, when people were asked what was the most important factor in their choice of detergent (洗衣粉), smell was rated highly, above ingredients and price. Now stores are becoming even more direct in their use of smell. The smell of fresh bread in a supermarket tends to encourage people to buy, and people selling their houses are recommended to have coffee being heated when potential buyers arrive. Suddenly smell is becoming big business. One company specializing in the use of smells to attract customers now has many large stores on its own list of customers. They find that when pleasant smells are filtered through a store’s air conditioning 　　system, people tend to spend longer in the store and buy more. Research shows that smells can increase people’s view of the value of a product. In a test, people looked at the same types of shoes in two rooms-one filled with purified air, the other with a smell of mixed flowers. 84u/o of the people preferred the shoes in the room with the smell of flowers. In fact, many said they would be 　　prepared to pay up to US$10 more for a pair. Smells also have other potential uses. Some companies are experimenting with different smells to produce different effects in their workers according to the time of day. For example, early in the morning they might put the smell of lemon in the air conditioning system to wake people up. In the middle of the morning, when the 　　atmosphere tends to become more tense, the smell of wood could be used to calm people down. Before lunchtime the smell of melting butter would encourage people to go to lunch on time. After lunch, when people often begin to lose concentration, the smell of mint(薄荷) would increase their alertness.

Which is the most appropriate title for the passage

A．How to avoid being affected by smells
B．Using smells to influence people
C．The power of our sense of smell
D．New smells in supermarkets