Frictional unemployment occurs when:
there is friction between an employer and employee.
a worker decides to quit one job to seek a different job.
a large corporation transfers a worker to another city.
college students go back to school at the end of the summer.

A worker decides to quit one job to seek a different job

Explanation:

Frictional unemployment is another type of unemployment within an economy. It is the time period between jobs when a worker is searching for or transitioning from one job to another. Frictional unemployment is always present to some degree in an economy. It occurs when there is a mismatch between the workers and jobs.