All people prefer colors that they can distinguish easily to colors that they have difficulty distinguishing. Infants can easily distinguish bright colors but, unlike adults, have difficulty distinguishing subtle shades. A brightly colored toy for infants sells better than the same toy in subtle shades at the same price. Which one of the following conclusions is most strongly supported by the information in the passage? ['The sales of toys for infants reflect the preferences of infants in at least one respect.', 'Toy makers study infants to determine what colors the infants can distinguish easily.', 'Infants prefer bright primary colors to bright secondary colors.', 'Color is the most important factor in determining which toys an infant will prefer to play with.']