Answer:
.d. is present even when labor markets are working well.
Step-by-step explanation:
Frictional unemployment occurs when one is searching for their first job. It also comes about when workers are shifting from one job to another. Frictional unemployment is naturally occurring. It is present even when the economy is considered to be in full employment.
Before a college graduate finds their first job, they will be frictionally unemployed. A worker in between jobs is also frictionally unemployed. During times of economic downturns, frictional unemployment does not increase like other forms of unemployment.