In the country of Ausmaila the working age population is 20 million, the participation rate is 80 percent, and employment is 14 million. The Bureau of Statistics for Ausmaila estimates that cyclical unemployment is 1,200,000 and frictional unemployment is 250,000. What is the natural rate of unemployment in Ausmaila? a. 7.5 percent b. 1.75 percent c. 3.75 percent d. 4.5 percent e. 5 percent