prep GMAT的一个题

The cotton farms of Country Q became so productive that the market could not absorb all that they produced.Consequently,cotton prices fell.The government tried to boost cotton prices by offer farmers who took 25 percent of their cotton acreage out of production direct support payments up to a specified maximum per farm. The government's program,if successful,will not be a net burden on the budget.which of the following,if ture,is the best basis for an explanation of how this could be so?

A Depressed cotton prices meant operating losses for cotton farms,and the government lost revenue from taxes on farm profits

B Cotton production in several countries other than Q declined slightly the year that the support-payment program went into effect in Q

C...

D The specified maximum per farm meant that for very large cotton farms the support payments were less per acre for those acres that were withdrawn from production than they were for smaller farms

E...

the answer is A,但是a不一定成立，因为价格下降总利润可能下降、不变或者上升，如果是后2者的情况，则政府税收不会减少=>补贴就成为Burden

D很绕，碰到这种句子我就犯晕，谁帮我解释一下？

thanks