Full employment, in context of determination of income, implies?

Option 1 -> Voluntary unemployment exists even at full employment as some people choose not to work.

Option 2 -> Full employment means no involuntary unemployment - everyone willing to work at prevailing wages can find jobs.

Option 3 -> Frictional unemployment (people between jobs) exists even at full employment as part of normal labor market dynamics.

Option 4 -> Full employment doesn't mean 100% employment; it allows for voluntary and frictional unemployment.

Hence, Option 2: Absence of involuntary unemployment -> In economic theory, particularly in Keynesian income determination models, full employment is defined as a situation where there is no involuntary unemployment. This means everyone who is willing and able to work at the current wage rate can find employment. Full employment does NOT mean zero unemployment - it still permits voluntary unemployment (people who choose not to work), frictional unemployment (people temporarily between jobs), and sometimes structural unemployment. The key distinction is that at full employment, there are no workers who want jobs at prevailing wages but cannot find them. -> correct