How did Lester Brown's predictions about U.S

dependence on basic raw materials and the power of the developing world over the United States hold up through the 1980s?
a. The prices of these materials went up, so Brown's predictions of increased vulnerability proved true.
b. The prices of these materials did not rise, but there were shortages of materials that increased U.S. vulnerability, proving Brown partly correct.
c. The prices of these materials went down, so Brown's predictions of increased vulnerability proved false.
d. The U.S. transitioned away from using these raw materials, which invalidated Brown's predictions.
e. None of these answers is correct.

Answer: c