Explanation:

Here’s what each option really means:

- Option 1: Money income

This is all the income people earn measured in terms of actual money—like rupees, euros, or dollars.

But just measuring national income at market prices isn’t quite the same as “money income.” It’s a broader measure.

- Option 2: Real income

Real income means the value of income after adjusting for inflation, so it reflects purchasing power—not just the raw cash amount.

- Option 3: Non-monetary income

This covers things people get that aren’t counted in cash, like home-grown food or unpaid work. It’s not what national income at market prices is about.

- Option 4: None of these

Sometimes, the best fit is “none of these” when none match precisely.

Let’s be precise:

Calculation of National Income at Market Prices actually refers to “National income at market prices,” which is neither just money income nor real income by itself.

So,

The correct answer here is Option: 4, None of these.

National income at market prices is a specific macroeconomic measurement and doesn’t directly match “money income,” “real income,” or “non-monetary income.”