Erosion of Americas farmland by wind and water has been a problem since settlers first put the prairies and grasslands under the plow in the nineteenth century By the 1930s, more than 282 million acres of farmland were damaged by erosion. After 40 years of conservation efforts, soil erosion has accelerated due to new demands placed on the land by heavy crop production. In the years ahead, soil erosion and the pollution problems it causes are likely to replace petroleum scarcity as the nation's most critical natural resource problem. The author points out in the passage that erosion in America ________a.occurs only in areas with no vegetationb.can become a more serious problem in the futurec.has damaged 282 million acres ever since settlers first put the prairies and grasslands under the plowd.has been so severe that it has forced people to abandon their settlements