Value added refers to the difference between the value of a product at the end of a production stage and the cost of inputs used in that stage. It represents the contribution of labor, capital, and other factors of production to the final value of the good, which is a fundamental concept in calculating national income and consumption taxes.

National saving is defined as Y - C - G. In this scenario, the provided values lead to a calculation where saving and investment are zero. While the explanation provided in the source is mathematically convoluted, the result D is accepted as the correct answer based on the provided key. This may reflect a specific closed-economy equilibrium condition where net injections and leakages balance at zero.

Gross Domestic Product (GDP) is the total monetary or market value of all the finished goods and services produced within a country's borders in a specific time period. It functions as a comprehensive scorecard of a given country’s economic health. While option C is also a general description, option A provides the precise technical definition used in national income accounting.

Purchasing power parity (PPP) adjusts for differences in the cost of living and price levels between countries. By equalizing the purchasing power of different currencies, economists can more accurately compare the actual standard of living and real income levels across diverse international economies.

National income represents the total value of all final goods and services produced by the residents of a country during a specific period, usually a year. It is the aggregate of all factor incomes—wages, rent, interest, and profit—earned by the citizens of a nation within that timeframe.

Standard of living is determined by real income, which is nominal income adjusted for inflation. If an individual's nominal income grows at a rate that exceeds the rate of inflation (as measured by the CPI), their purchasing power increases. In this scenario, the income growth of 47% outpaces the inflation rate, indicating that the individual can afford more goods and services than before, thus raising their standard of living.

According to the national saving identity, national saving equals domestic investment plus net capital outflow. If private saving increases while domestic investment remains constant, the excess savings must be invested abroad, increasing net capital outflow. Since net capital outflow must equal net exports, net exports will increase by the same amount.

Net investment represents the actual addition to the capital stock of an economy. It is calculated by taking the gross investment (total spending on new capital goods) and subtracting the capital consumption allowance, which accounts for the depreciation or wear and tear of existing capital assets during the production process.

Real GNP measures the total market value of all final goods and services produced by a nation's residents. However, it is a crude measure of welfare because it only accounts for market-based transactions. It excludes non-market activities, such as unpaid domestic labor, volunteer work, and household production. Since these activities contribute significantly to the quality of life and overall economic well-being, their omission leads to an underestimation of the true welfare of a society.

National saving is the sum of private saving (disposable income minus consumption) and public saving (tax revenue minus government spending). It represents the portion of national income that is not consumed by households or the government, and it is the source of funds for domestic investment.