Old rose varieties have less vibrant colors than modern rose varieties, but are superior in fragrance. This situation has arisen because the modern rose varieties were developed to meet customer demand and marketed mainly through catalogs: colors, but not fragrances, can be photographed. Which one of the following, if true, most strengthens the support for the causal claim made above? ['People in earlier times were interested in the fragrances of roses as well as their colors.', 'State-of-the-art photographic equipment makes possible unprecedentedly accurate color reproductions of roses.', 'Breeding roses to enhance one trait often has unanticipated consequences for other traits.', 'People in earlier times would have found the vibrant colors of modern roses too harsh.']