Only when total production expands faster than the rate of labor force growth plus the rate of productivity increase and minus the rate with average annual hours fall so does the unemployment rate.
A. at which average annual hours fall does the umemployment rate fall.
B. which average annual hours fall so does the umemployment rate.
C. in which average annual hours fall and so does the umemployment.
D. which average annual hours fall does the umemployment rate fall.