Farmers in developing countries claim that the United States government, through farm subsidies, is responsible for the artificially low global price of wheat. Because the U.S. government buys whatever wheat American farmers are unable to sell on the open market, American farmers have no incentive to modulate the size of their crops according to the needs of the global market. As a result, American farmers routinely produce more wheat than the global market can absorb and the global price of wheat is kept low. Without these subsidies, the farmers in developing economies claim, American farmers would produce only the amount of wheat that they could sell on the open market and the global price of wheat would rise.

Which of the following, if true, most weakens the claims of the farmers in developing countries regarding the price of wheat?

"¢ Wheat that is not processed for consumption is often used for certain industrial applications.
"¢ Non-governmental buyers of wheat and wheat products are able to predict how much wheat they will need several years in advance.
"¢ The United States government offers similar subsidies to soybean farmers, though the global price of soybeans is significantly higher than that of wheat.
"¢ Other countries, such as Canada and Russia, are likely to produce more wheat if the United States were to reduce its output.
"¢ The price of sorghum, a crop for which the United States government offers no subsidies, is lower than that of wheat.

The OA is [spoiler]D[/spoiler]

My ques is why C is wrong as this is a weaken question and we can take any outside information true.

and in C the soyabean prices are compared with the wheat prices which should not be wrong in Weaken Type ques.

Please clarify