The Primary Advantage of Automatic Vending as a Form of Retailing

The primary advantage of automatic vending as a form of retailing is that:

A) it offers a low-cost, personal method of selling products.
B) it provides continuous service to consumers.
C) since vending machines must be serviced frequently, the products they sell are always fresh.
D) vending machines require very few repairs.
E) it eliminates the need for sales personnel.