Correct Answer: intermediate, final

Solution : The correct answer is (a) intermediate, final.

National income refers to the total value of all goods and services produced within a country's borders during a specific period, typically a year. It is an important measure of a country's economic performance and is used to assess the overall level of economic activity.

In the context of national income, "intermediate goods" are those goods that are used as inputs in the production process but are not directly consumed by end-users. These goods are typically used in the production of other goods or services. Examples of intermediate goods include raw materials, components, and partially finished products. The value of intermediate goods is not included in the calculation of national income to avoid double-counting since their value is already reflected in the final goods and services they contribute to.

On the other hand, "final goods and services" refer to those goods and services that are directly consumed by individuals, businesses, or the government. These are the end products that are purchased for their final use or consumption. Final goods and services include items such as food, clothing, cars, housing, entertainment, healthcare services, and so on. The value of final goods and services is included in the calculation of national income since it represents the value added to the economy.

Therefore, national income encompasses both the value of intermediate goods and the value of final goods and services. However, only the value of final goods and services is directly included in the calculation of national income to avoid duplicating the value of intermediate goods.