Final answer:
Money serves as a measure of value when it acts as a unit of account, providing a common denomination for the value of goods and services, such as a bill's worth in dollars.
Step-by-step explanation:
The statement that shows money as a "measure of value" is "This bill is worth twenty dollars." Money, in its role as a unit of account, acts as a common denominator that simplifies thinking about trade-offs, as it gives a standard measure for the value of goods and services.
For instance, an accountant may charge you $100 for filing your tax return, and you can compare this cost directly with purchasing two pairs of shoes at $50 each, illustrating the convenience of having a standardized measure of value.