When cell phones were first entering the market, they were relatively large and reception was undependable. All cell phones were essentially the same. But as the technology developed, many competitors entered, introducing features unique to their phones. Today, cell phones are only a small fraction of the size and weight of their predecessors. Consumers can buy cell phones with color screens, cameras, Internet access, daily planners, or voice activation (and any combination of these features). The history of the cell phone demonstrates what marketing trend?
a. Markets evolve toward greater heterogeneity over time. b. Product diversity declines as more market segments develop. c. Technology advances are almost always introduced by market leaders. d. Market segmentation usually forces existing companies out of business. e. New competitors seldom bring innovation into an existing market.