It has been found that less than one shopper in five makes a complete shopping list before going to the store. The reason for this is that seven out of ten of today's purchases  are decided in the store, where the shoppers tend toward impulse  buying. Buying groceries on impulse had risen for the past forty years, and this rise has coincided  with the growth of self-service shopping. However, in grocery stores where clerks wait on customers there is much less impulse buying. It is hard for people to buy on impulse if they have to address a clerk. Psychologists have joined forces with merchandising  experts. It is their job to persuade people to buy products which they may not need or even want until they see them attractively presented. It was discovered by the psychologists that shoppers want help in their purchases. Having so many choices confuses them, and they prefer the package that attracts them. Therefore, it is now more usual for food packers to pay attention to their package design. Attraction depends heavily on the position of the product on the shelf, however. Thus, persuading the shopper to buy is easier if the product is located at eye-level. Shoppers tend to buy the products put on   _  .
the top shelf the bottom shelf the shelf which people can see easily the shelf where there is less confusion