Since the Dust Bowl of the 1930s, ______________

Since the Dust Bowl of the 1930s, ______________.

A) we have become much more conscious of the value of our soil
B) we have been able to devise viable methods of reclaiming grasslands lost to desertification
C) we no longer overgraze or overplow our marginal agricultural areas
D) the use of fertilizers and irrigation has increased the amount of arable land in the United States
E) soil erosion is once again approaching Dust Bowl rates