Indicate whether each of the following statements pertains to microeconomics or macroeconomics:

a. The unemployment rate in the United States was 3.7 percent in 2019.

b. Workers at the Sleepy Eye grain elevator are paid $10 per hour.

c. The productivity of American workers as a whole increased by more than 2 percent per year in the last decade.

d. The money or nominal wages of nursing aides increased by 2 percent in 2019.

e. The Alpo dog food plant in Bowser, Indiana, laid off 15 workers last month.