The United States government generally tries to protect valuable natural resources. But one resource has been ignored for too long. In the United States, each bushel of corn produced might result in the loss of as much as two bushels of topsoil. Moreover, in the last 100 years, the topsoil in many states, which once was about fourteen inches thick, has been eroded to only six or eight inches. Nonetheless, federal expenditures for nationwide soil conservation programs have remained at ridiculously low levels. Total federal expenditures for nationwide soil conservation programs have been less than the allocations of some individual states.Which one of the following best expresses the main point of the argument?
(A) Corn is not a cost-effective product and substitutes should be found where possible.
(B) A layer of topsoil only six to eight inches thick cannot support the continued cultivation of corn.
(C) Soil conservation is a responsibility of the federal government, not the states.
(D) The federal government's expenditures for soil conservation in the various states have been inequitable.
(E) The federal government should spend much more on soil conservation than it has been spending.

The paragraph we are analyzing is not attacking corn. At no point was said that corn should be substituted; so we can eliminate letter A. Letter B is just something we can assume from the text; it is not its main point. From it, the main point of the argument will arise. Letter C is incorrect because the states and the federal government all have the responsibility. The paragraph does not say the states should be exempt. Letter D uses the word inequitable for the expenditures, meaning they have been unfair or discriminatory. Nothing was said about that - we do not know if the federal government helps some states more than others. Finally, letter E is the correct one. The focus of this paragraph is the fact that the federal government is not spending enough on soil conservation. As was stated, "federal expenditures for nationwide soil conservation programs have remained at ridiculously low levels." The federal government clearly should be doing more than it is, investing more in a solution for the soil problem before it gets to an unsolvable point. We can safely say letter E is the best option.