Ccording to the law of supply, the quantity of an item supplied will rise as a result of: a) an increase in the number of firms producing the item. b) decreases in the prices of inputs used to produce the item. c) an increase in the price of the item. d) a decrease in the price of the item.

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?