Why, According to Behavioral Economics, Would Supermarkets Place Gum, Candy

Why, according to behavioral economics, would supermarkets place gum, candy, and other small convenience items near the cash registers?

A) Those are the shelving locations that minimize costs.
B) Stores try to make frequently purchased items quicker and easier for consumers to access.
C) Smaller items tend to fall through shopping cart holes, so stores reduce that problem for consumers by having smaller items at the checkout stands.
D) Many of these are small items that people will buy on an impulse.