Identify the term that is called National income of a Economy.

$NNP_{FC}$

The correct answer is option (4) : $NNP_{FC}$

The term that is called the National income of an economy is  $NNP_{FC}$ which stands for Net National Product at Factor Cost. This measure represents the total income generated within an economy after accounting for depreciation (or wear and tear on capital) and other operating costs.