Read the following passage:

The overall point of the CPI is to determine what the value of the medium of exchange has in the economy. We go to the grocery store with a budget, and what we were able to buy a year ago may change depending on the value that our medium of exchange holds. Have you ever been told a story from a grandparent about how much they could buy with just one dollar? It is because the medium of exchange has changed in value over time along with the cost of living. The same dollar will no longer purchase the same goods for the same price.

What is the purpose of the text?

Group of answer choices

To introduce and describe CPI.

The medium of exchange has changed in value over time along with the cost of living.

To explain that the same dollar will no longer purchase the same goods for the same price.

To explain the purpose of the CPI as a measure of the value of the medium of exchange in the economy and how it can affect the purchasing power of a dollar over time.

The purpose of the text is to explain that the same dollar will no longer purchase the same goods for the same price.

The purpose of the text is to explain that the same dollar will no longer purchase the same goods for the same price. This is evident from the passage's discussion of how the value of the medium of exchange, represented by currency, can change over time, impacting the purchasing power of individuals. The example of grandparents being able to buy more with just one dollar serves to illustrate this point. Therefore, the correct answer is "To explain that the same dollar will no longer purchase the same goods for the same price."