The correct answer is: a) Gross National Income (GNI) per capita.
Gross National Income (GNI) per capita is a measure of a country’s economic output per person. It is calculated by dividing a country’s gross national income (GNI) by its population. GNI is the total value of all goods and services produced by a country’s economy in a year, plus income earned by its citizens from abroad, minus income paid to foreign residents.
GNI per capita is a widely used measure of a country’s standard of living. It is often used to compare the economic performance of different countries. However, it is important to note that GNI per capita does not take into account the distribution of income within a country. A country with a high GNI per capita may still have a large number of people living in poverty if the income is not evenly distributed.
The other options are not as good measures of standard of living. Access to basic necessities is a measure of whether people have access to basic goods and services such as food, water, shelter, and healthcare. Consumer spending patterns are a measure of how people spend their money. Wealth inequality is a measure of the gap between the rich and the poor.
While all of these measures can be useful in understanding a country’s standard of living, GNI per capita is the most widely used measure. It is a simple and straightforward measure that can be easily compared across countries.