..........level of income is that level of income where all the factors of production are fully employed in the production process.

Full employment.

The correct answer is Option (3) → Full employment.

The full employment level of income refers to the level of national income or output at which all factors of production — labour, land, capital, and enterprise — are fully and efficiently employed in the production process.

At this level:

• There is no involuntary unemployment in the economy.

• The economy produces its potential output or maximum sustainable level of income.