Which of the following represents frictional unemployment? i) The demand for refrigerators falls when the economy enters a recession, and refrigerator manufacturers lay off some of their workers. ii) General Motors decides to close its U.S. factories and relocate its car manufacturing division to Canada. iii) After graduation you take a job in financial services, but the long hours don't appeal to you so you quit to find a job elsewhere. iv) Juan's fishing business can't cover its costs, so it closes. Juan is now looking for a new job.