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? ["The federal government's expenditures for soil conservation in the various states have been inequitable.", 'Corn is not a cost-effective product and substitutes should be found where possible.', 'Soil conservation is a responsibility of the federal government, not the states.', 'The federal government should spend much more on soil conservation than it has been spending.']