题目选项分析

Suriland cannot both export wheat and keep bread plentiful and affordable in Suriland. Accordingly, Suriland's wheat farmers are required to sell their crop to the government, whichpays them a dollar per bushel less than the price on the world market. Therefore, if the farmers could sell their wheat on the world market, they would make a dollar per bushel more, less any additional transportation and brokerage costs they would have to pay.

Which of the following, if true, most seriously weakens the argument?

【选项】Sale of a substantial proportion of Suriland's wheat crop on the world market would probably depress the price of wheat.