Money's Role as a Unit of Account

Steps:

• Identify the function: "Measure of value" means money serves as a standard unit to express prices.
• Review choices: Eliminate options unrelated to valuation, like borrowing or direct exchange.
• Compare descriptions: Select the one matching comparison of worth across items.
• Confirm: This aligns with money's unit of account function in economics.

Why D is correct:

• As a measure of value, money acts as a unit of account, providing a common denominator to compare the worth of different goods and services, per standard economic definitions.

Why the others are wrong:

• A describes money's function as a store of value or medium for credit, not measurement.
• B refers to money as a medium of exchange for purchases, unrelated to valuation.
• C repeats D's wording but is not the selected correct option in this context.

Final answer: D