Companies wishing to boost sales of merchandise should use in-store displays to catch customers' attention. According to a marketing study, today' s busy shoppers have less time for coupon-clipping and pay little attention to direct-mail advertising; instead, they make two-thirds of their buying decisions on the spot at the store. Which one of the following is an assumption that the argument requires? ["Many of today's shoppers are too busy to pay careful attention to in-store displays.", 'Coupons and direct-mail advertising were at one time more effective means of boosting sales of merchandise than they are now.', "Companies are increasingly using in-store displays to catch customers' attention.", "In-store displays that catch customers' attention increase the likelihood that customers will decide on the spot to buy the company's merchandise."]