Newspaper: Increases in produce prices apparently have led to an increase in the planting of personal gardens. The two largest retail seed companies each reported sales increases of around 19 percent in the last year alone, a year in which the price of produce spiked. Which one of the following, if true, most seriously weakens the newspaper's argument? ['A large retail seed company went out of business early last year.', 'Community gardens report that waiting lists for renting garden plots have gotten longer over the last year.', 'Personal gardens are usually popular in economic downturns.', 'Increases in produce prices are largely driven by increases in the fuel costs of bringing crops to market.']